It is good you are pursuing an evaluation and I hope you get helpful answers in that process.
I agree with your general point that for kids who tend to be obsessive (and I'll to that 2e, depressive, anxious, etc.) it often doesn't work well to take away all structure. There needs to be routine and limits.
As far as not being able to afford activities, I certainly understand that. I would encourage you to try to cast a wide net in your community and look for less expensive options. As another poster mentioned many game stores have free game nights. Another thought would be to look for adults who might share an interest with him - maybe a friend has a retired dad who likes military history or something like that.
Also, if you have not already done so maybe it would be a good time to apply for financial assistance through DYS to support his education or activities.
