Civ Rev is the best civ and I may have written a 241 page design document for a sequel.
Speaking of balancing a day job and creative hobbies, I have thoughts about this. I’ve always done creative work in my spare time and have been very fortunate to get involved in some projects that have had a wider impact than I could have hoped for.
I think the best advice I can give based on my experience of having done so is to be patient. Anything you do is going to take a long time and probably not come out at the same quality level as professionally done work so you need to be prepared to be happy with small increments of work slowly adding up to something potentially massive. You need to learn not so much about how to pace yourself (which is what professionals do) but to recognise when you’re doing productive work and it’s a good time to push yourself, and when you’re doing non-productive work and therefore its probably good to step back and give yourself a break. Key to this is recognising burnout, which is going to happen especially if you’re working on something that takes 10 or more years to do, which is the time scale you may end up looking at when you can only spend small chunks of your time on a project. Don’t ever beat yourself up about how much you’re getting done and whether you’re doing the right thing. You have the luxury of not needing your creative hobby to support yourself or anyone else and so you can experiment and do projects that on their face are completely useless (like my 241 page Civ Rev design) but are scratching a creative itch.
I can’t speak to collaboration much, because I don’t think over the time scales that I work on that you’re going to get many direct collaborations. The board game stuff is an exception, but the particular design model I’ve worked inside is where collaboration is serial rather than parallel: I would get the design and run with it for a while before handing it off to someone else.
There’s also a lot of advice that creative professionals give each other that may not necessarily apply if you’re a part timer. For instance, while I appreciate “Fail quick and fail often”, cultivating a community in order to get the feedback needed to figure out if you’re failing is in itself probably a full time job, so I feel like I’m better off relying on intuition to figure out if I’m succeeding or failing.
I’m only one data point and a pretty weird one, so I’m not sure if you should listen to anything I have to say, but just putting it out there.