there should not be pro perks

I liked the concept of League in BOII, but Treyarch didn't deliver it properly. The balance of it was waaaay off. They were putting unranked people with Gold and Diamond league people and they basically said "go finish 5 games and we'll see where you fit in between the spectrum." That's like putting a team of non-prestigers against 10th or max prestigers. How is that even remotely a good idea?

I don't know how you mean "a decent campaign", I think almost all the COD campaigns were pretty good, especially MW3, BLOPs and Ghosts campaign. From what I've seen of the trailers SH released, it looks similar to BOII's campaign which I didn't care for.

Weapon balancing is always an issue with COD, there really is no way of getting around that, as long as there are no more Type 95 1-shot burst weapons it should be fine.

Pro perks would definitely be a good addition, I missed them from the IW games, Treyarch doesn't seem to like that idea. I don't know if it's a dev specific royalty that doesn't allow Treyarch to use it, or if they just don't like it all together. Hopefully SH does perks the right way.