I play with eco footprint off, and the only issue I've come across is that occasionally one of my sims will randomly get a "fresh air" happy moodlet for no reason. Other than that, no problem keeping it off.
As others have said, you can either turn off NAP voting right off the bat, or you can vote in some NAPs and then turn them off if you want, and the NAPs will stay as-is. It is not hard at all to earn enough influence points to always win the vote. The only problem I have is that the Promote Creative Arts NAP causes NPCs to play with clay excessively. It's super annoying. I use Bienchen's mod called NAP Overhaul (noautonomousmoldclay module) to get rid of that issue.
I can't think of any other bugs specific to this EP in my game. I recommend buying it for the reasons you listed. The bb alone is great.
ETA: @GlacierSnow, your question about everyone playing with clay is answered here in my post.
