Are you supposed to not enter the roundabout if you see a ped going to cross the road where you would exit? Or stop in the middle if they step into your exit road? Or keep going around and around until your exit is clear?

You stop and wait for pedestrians to pass, then exit or enter the traffic circle

As a pedestrian, can you walk counter to the spin? Can you cross the circle ⭕ or do you have to go around?

Yep. For you it's just a walkway that goes all way around the traffic circle, with no extra rules. Though sometimes there's just a bypass line for pedestrians, if there's 1 or more exits to highway or something where pedestrians do not go

You enter the roundabout normally.

If the pedestrian is crossing your exit, you wait by your exit until they are clear.

Most pedestrians will try crossing when they are sure nobody is about to enter, but obviously that is never a guarantee, and pedestrians have right of way.

you shouldn't be navigating a roundabout at such a speed where you cannot stop, so coming to a gentle stop to let them pass shouldn't be an issue.