1. if ive got a game with mods on steam, will it work with the mods on steam deck?

2. can i use a controller (eg PS5 controller) on steam deck?

3. do games use the same amount of storage on the deck as they would on a pc? As ive found a deck online thats 64GB and most games are 60+ on their own

Sorry if these are stupid questions, im new to gaming as a whole