Street pass should still be a thing. Although now its just if you pass another console as my 3 consoles do streetpass when I want to use that. It is the relay points which have been taken down that dont work.As long as you don't region change, yes you'll retain access to the eShop, streetpass (if it is still going) and online & local multiplayer. You can also install GBA VC injects on your home menu and dump 3DS cartridge games to cia and install them on your home menu.