Using account on another pc bannable?

You pay for platform access on a servce account, not single machine licenses. Aside from previous statements you would have no issues.

It's not bannable but it locks out the account, for security reason.

Its fine, I've logged into my account from 7 different PCs in 2 different countries, all that happens is they lock your account for "suspicious activity" and send you an email telling you to reset your password. Once you do this you are free to log in and play as normal.

lol I've been playing on 3 different PC and locations. Don't worry, I never heard a game company ban you from different places. That's just dumb.

As long as it's your friend playing on his account, no issues.

If it's you playing his account, it's bannable, and the giant red flag would be him trying to log in while you are playing his character, or vice versa.

I sure hope not. I've been doing it for ages.

What about if person is going between PS3/PS4 and PC?

I hope that isn't a problem...though I'm thinking for me it won't be because I use a One-Time Password.