I think you'll find very few DMs who allow "everything" at their table.
I use things from any source that fits the flavor I'm going for. Up until the end of last session, I was using all of the Freeport material, Alchemy & Herblaists (Bastion), a variant sorcerer I've pieced together from several sources, and spells from half a dozen print and pdf sources. Oh, and Stone to Steel for equipment options (Monkey God). Next session the campaign is going in a radically new direction, and I don't yet know if I'll be bringing in new player options. Fortunately for me, we aren't playing again until March 20th. That gives me plenty of time.
The way I work things is this: a player tells me what sort of thing they want, and I find an acceptable source. They don't just go out and willy-nilly collect PrCs, feats and so forth.
I'm sure I could run a perfectly decent campaign from just the core books, but I've got all this stuff, so I might as well use it, eh?