If I could put this post in a time machine and send it to my younger self, I think I could have saved myself an awful lot of trouble. You made so many ridiculously awesome points about emotional compatibility that I don't even know which to single out, so I'll just say I'm relieved I found a partner that I have that with in spades. (Also: your needs sound like they came out of my head, and I'm a Gemini. Maybe it's my Taurus moon. XD)
Regarding hobbies: I think compatibility there is more important than people give it credit for, but that's much less about the actual hobbies and more about how the people in the relationship view and go about their hobbies, whether they're shared ones or not. I've found that this is one of those worldview things that can cause problems if you're not relatively on the same page. 'Cause even when people share the same interests, they may not go about them in the same way, and you need to have room to let each other go about things in the manner that's most comfortable and/or fun.
I'll just use gaming as an example since it's my main hobby. Specifically when it comes to WoW, I'm a progression-oriented raider, meaning that just seeing the dungeon and getting a couple of pieces of shiny loot isn't enough for me. I have to beat every boss in there to the end, preferably on hard mode. I'm the kind of player who runs spreadsheets and simulation programs to min-max my characters to the Nth degree in order to eke out every ounce of performance I can. I frequent sites with names like Elitist Jerks. I may not get shouty over voice chat at people who make mistakes, but I am very competitive and I'm definitely a perfectionist; my definition of fun includes being prepared and trying your best. My definition of gaming euphoria is dying to Sindragosa on hard mode for weeks at a time, then finally killing the damn dragon and cheering and hollering over voice chat with your friends. I'm the type of raider who considers it a failure if I'm not in the top three for damage done on a boss fight, and I do boatloads of research on the classes I play in order to make sure I stay there (as well as being aware of the utility-type abilities I can bring to the fight to make it easier for the raid). I'm also damned good at what I do, and am always one of the go-to mentors in my guilds for people who need help with their characters.
Raiding is also the kind of activity that requires hours of time, and demands a lot of focus. You have either 9 or 24 other people relying on you to know your role and not fuck things up for everyone (triply so if you're in any sort of mission-critical role like healing or tanking). I may not be raiding 10-15 hours a week anymore (thank gods), and I may not be doing crazy hard modes like I used to, but I do spend a lot of time on it.
Even in single player games, I'm the one that has to go for 100% completion, I have to max out my characters' levels/equipment/stats, I have to find/beat all the secret bosses and get all the uber loot. I have over 200 hours clocked on my main Vagrant Story save file and at least 70% of those hours were spent farming soldiers for gear and tweaking it in the workshops to get the best possible armor and weapons. I write FAQs and guides.
In other words, I'm a hardcore gamer, and I'm very set in my ways about it. If my partner can't understand or appreciate that, it's going to be a problem, even if they themselves play video games. For all his (many) faults, Ryan understood that because he was the exact same way. I think if we hadn't been raiding together, we would have broken up long before we actually did. Pete, OTOH, didn't get that, which is why I stopped gaming with him--he couldn't respect my skill, and would pitch fits whenever I beat him at anything, because how dare a woman who's been gaming her whole life be better than her boyfriend whose first gaming experience was the original Playstation. I don't take a casual approach to gaming, and when I'm forced to do so or feel like I have to stop gaming altogether in order to keep the peace in a relationship, I tend to be pretty miserable. It's less about the gaming itself--even though I love it to bits--and more about feeling like my wants and needs are being disregarded. Which goes right into the emotional needs stuff you were talking about. (And now you know the root of what made me so upset re: Kingdom Hearts 2, Dirge of Cerberus, and FF12 when I was living with J.)
Long comment is long
Regarding hobbies: I think compatibility there is more important than people give it credit for, but that's much less about the actual hobbies and more about how the people in the relationship view and go about their hobbies, whether they're shared ones or not. I've found that this is one of those worldview things that can cause problems if you're not relatively on the same page. 'Cause even when people share the same interests, they may not go about them in the same way, and you need to have room to let each other go about things in the manner that's most comfortable and/or fun.
I'll just use gaming as an example since it's my main hobby. Specifically when it comes to WoW, I'm a progression-oriented raider, meaning that just seeing the dungeon and getting a couple of pieces of shiny loot isn't enough for me. I have to beat every boss in there to the end, preferably on hard mode. I'm the kind of player who runs spreadsheets and simulation programs to min-max my characters to the Nth degree in order to eke out every ounce of performance I can. I frequent sites with names like Elitist Jerks. I may not get shouty over voice chat at people who make mistakes, but I am very competitive and I'm definitely a perfectionist; my definition of fun includes being prepared and trying your best. My definition of gaming euphoria is dying to Sindragosa on hard mode for weeks at a time, then finally killing the damn dragon and cheering and hollering over voice chat with your friends. I'm the type of raider who considers it a failure if I'm not in the top three for damage done on a boss fight, and I do boatloads of research on the classes I play in order to make sure I stay there (as well as being aware of the utility-type abilities I can bring to the fight to make it easier for the raid). I'm also damned good at what I do, and am always one of the go-to mentors in my guilds for people who need help with their characters.
Raiding is also the kind of activity that requires hours of time, and demands a lot of focus. You have either 9 or 24 other people relying on you to know your role and not fuck things up for everyone (triply so if you're in any sort of mission-critical role like healing or tanking). I may not be raiding 10-15 hours a week anymore (thank gods), and I may not be doing crazy hard modes like I used to, but I do spend a lot of time on it.
Even in single player games, I'm the one that has to go for 100% completion, I have to max out my characters' levels/equipment/stats, I have to find/beat all the secret bosses and get all the uber loot. I have over 200 hours clocked on my main Vagrant Story save file and at least 70% of those hours were spent farming soldiers for gear and tweaking it in the workshops to get the best possible armor and weapons. I write FAQs and guides.
In other words, I'm a hardcore gamer, and I'm very set in my ways about it. If my partner can't understand or appreciate that, it's going to be a problem, even if they themselves play video games. For all his (many) faults, Ryan understood that because he was the exact same way. I think if we hadn't been raiding together, we would have broken up long before we actually did. Pete, OTOH, didn't get that, which is why I stopped gaming with him--he couldn't respect my skill, and would pitch fits whenever I beat him at anything, because how dare a woman who's been gaming her whole life be better than her boyfriend whose first gaming experience was the original Playstation. I don't take a casual approach to gaming, and when I'm forced to do so or feel like I have to stop gaming altogether in order to keep the peace in a relationship, I tend to be pretty miserable. It's less about the gaming itself--even though I love it to bits--and more about feeling like my wants and needs are being disregarded. Which goes right into the emotional needs stuff you were talking about. (And now you know the root of what made me so upset re: Kingdom Hearts 2, Dirge of Cerberus, and FF12 when I was living with J.)