I added randomized pinning/following, but will be very surprised if that makes one iota of difference as far as suspensions are concerned.
I'm convinced that suspensions come from reviews triggered by user spam reports (often because the keywords were poorly chosen for the job or Pinterest doesn't have enough pins that actually match the keywords and so shows unrelated stuff) and by a few automated processes that happen very early on in the account. And I believe sites blocks come from either pinning too fast to one domain or also from users reporting the pin/site as spam and it being reviewed. I don't think the timing of the pins have much to do with anything.
If I'm wrong please post back and tell me, but don't be surprised if varying pinning has nothing to do with it.