response to last question
huh
well, that depends
if you're casual and just need the manual, it's less than a AAA game, and with how much more playability it has, no, that's not expensive. Once you start adding more books (DM Guide, Monster Manual, Guide to Everything, etc.), it gets ungodly expensive. I don't know what actually having to make the rules means, but I assume you're asking how rigid the rules are and if you have to follow them. You do, and they're rigid to the point of functionality, but it kind of flows.
TL;DR, mixed and (i assume) no