I didn't really decide to go any route... I honestly have very little idea what I'm doing... I mean, like I've never done any of this before. I'm sure most of what I've done will break at some point, though I can't imagine anything will break unless FG makes major changes to how it works (something akin to the 3.2 update). I am hoping to go through everything I've got and "fix" it in the ways you are talking about.
Basically I copied all of the existing info from the CoreRPG & 5E rulesets, then modified anything that looked broken. If it looked the way I intended, then I left it alone.
Again, I know for sure I did a lot of this flat our wrong.