Yes, I’d also say that Facebook is the strictest, I guess everyone wanted to spam them as they were the biggest so they put a lot of work into preventing that. It’s still doable, not spam but good quality marketing but you really have to take care and know what you’re doing.
Instagram is moderate, they can ban accounts very fast and it’s game over, but that mostly happens with new accounts, if you’re over a certain limit of followers they start being a lot more permissive with what you can do, so if you manage to grow them to that point you’re good
Pinterest is moderate as well, you can still bring a lot of traffic from posting to pinterest and having some seed accounts help out with the repins.
Most permissive I’d have to say are Twitter and G+ though, you can get away with a lot of them and still be ok, still bans happen but it’s a lot harder to get there.