a) names are often case sensitive, good to stick with it
b) that I’m not sure of, you’ll have to experiment
c) Yes, too many IDs 
Still not exactly sure how that’s going to work yet.
You -might- get problems trying to put everything in one data structure, not sure about that yet. Because what’s really elegant about object orientated programming ( which unreal is ), is that objects know about themselves and know what they can / can’t do. You’re taking a sort of old school FORTRAN type approach here, which will mean you just have one massive chunk of code which is constantly hammering this central data structure and will probably get pretty fiddly.
For instance, a season block knows that it fits with another season block, of the right type. It just knows that.
With this approach, you have to do all this looking up ‘what kind of block is it’, ‘what kind of block does it fit with’… see what I mean?