With a pit pass, can you watch race from infield? And is there a pedestrian bridge or tunnel between grandstands and pits? I've never been to this track.

It's a gate you can't cross

Yes you can but once your in you are there for the race. The crossover is actually crossing the track right near the start/finish line.

Yes you can watch the races from the pits with the exception of a couple of races. There are crossover gates on the from straight away and of course you can use the South pit gate.

No pit access that I've seen, but I've not looked for pit access either. There is no infield spectator access.