I only change rules if the official rule is negatively impacting our fun. That can mean a lot of things, of course, but usually it has to either be frustrating, hard to remember, or actively kill some specific sort of enjoyment.
Like, change the lore of goblins or dragons or elves or whatever? I don't usually go crazy but I like to have a few specific elements that differentiate this world from the core assumptions. I am very loose with world building and don't put much stock in "lore" as a component of fun.
Gnomes are the worst.
I don't usually police character generation. And I usually regret that about half a session in to the campaign.
If I own it, we can use it. Also, if it is available on Fantasy grounds (my VTT of choice due mostly to sunk cost.) Generally speaking i don't care for player focused mechanics added to the game, but like I said I try to stay out of character generation.
