Well, like any player to be here long term he will have to be the RB#2 if he isn't playing STs or he won't be on the game day roster, but the expectation when you drafted him is he will be. So I think you can say it about any player and I don't view that as a negative statement. Personally I think he will be the RB2 at some point this year (I mean who else do we really have?) but certainly by next if he is who many think he is. He won't ever be a bell cow back but his tape says he can run the ball and be a Swiss army knife type and the type of guy who can help a team even if only getting a few touches a game due t this big play ability.
As far as special teams go he won't be running down on kicks and punts, but I think he has the skill set to be a return guy - at least the #2 guy deep on kickoffs. Since he never returned punts and barely returned kicks I certainly wouldn't expect him to do it better than Turpin year 1, if ever. Perhaps it may eventually be his role but I don't think it will be this year. Interestingly enough I was reading where he made sure to showcase himself returning punts on his visits to shower can do it.
Lastly, I totally agree on pass protecting. He just isn't likely going to do it well at this level, but a lot of 3rd down receiving backs aren't great blockers and they become more a quick dump off option. sometimes you just need to be able to slow a guy down for a half second. Our OL should be OK when not facing a blitz. No OL will be perfect but we've been good enough to give our QB time to throw or dump off or throw away. We need to just keep working with him on it. Not to compare it to this but the way teams beat the Bears 46 D was to just start putting more WRs in patterns then they could cover. Our issue on blitzes has been more the miscommunication between our QB and WRs. Every other team seems to know what they are doing on hot reads but we don't. QB, WR, coach...not sure who's fault but it's been an issue for a while now. Also we played Pollard a lot on 3rd downs last year even though Zeke was the far superior pass protector, so it may not just be the best pass protector back there