I would keep Zimmerman over Latos, because he's in a more pitcher-friendly park than Latos, which could help your perifery numbers and overall points. Not sure I would keep 3 pitchers though, as there are usually plenty of starters available in a draft and as the season wears on that can help your team. I don't think you can lose with any of the 4 position players. The only sure guy in this group is Cabrera, as you have a track record to see how he has done over the past few years. I think he will be even better under Francona, who seems to get the best out of people when he first takes over. Plus, the division Cleveland is in is not over-whelming in pitching prowess other than Detroit. Rizzo and Rosario are 2nd year players now and sometimes take a step back and you have to be willing to live with that for the time being. I believe both will be good players as they develop, while Myers is still unknown with plenty of hype. Will he even start in the majors?? You have a nice situation to be in and good luck.
With only 6 keepers, and 2 great SP already, I might gamble on keeping 2 hitters from your list. Rosario has a chance to hit 30 HR as a catcher. Rizzo may not be amazing in 2013, but he should be solid, and he will improve. Wil Myers is tempting, but it seems Tampa Bay doesn't really have room for him for now, and he has yet to prove anything at the big-league level.
Can you make trades? I bet you could get some decent returns on packaging 2-3 of your players for a stud bat.
Like varrys, I like Zimmermann better than Latos as well. He's taken steps forward the past two years and is only gonna get better. Latos may get more K's, but Zimm should have the better era & whip. I like Cabrera but when looking at him I see him as more of the guy you saw last year than in 2011. I don't see that power being there on a regular basis. He's good, but is he 6th round good (well maybe in a 16 team league he is, I just saw the size of your league). As a Rosario owner I'm torn as I don't even know what to do with him. Catcher is deep this year and if you let him go you're sure to get someone back you can live with. He has big power potential, but I worry about his ability to stick at the catcher position. Not to mention you already have Posey. Myers has big time potential, but there are a lot of established players I would take before grabing him in round 6. I usually try and grab guys like this in the mid rounds once I have my team somewhat established, but in your league around round 10 sounds like a better plan. Rizzo took a big step last year and like Rosario & Myers has a big time potential. The only question about him is if he can continue to do this at the ML level.
Given the youth of your first 4 keepers, I'd keep Rizzo because if he works out you have 5 young guys to build around each and every year. The 6th one i'm torn on as all three have their advantages. Zimm would be a great #3, but I'm personally against this as 3 pitchers with your first 6 picks is a little much (even in a league your size). Cabrera would set the SS position which gets thin after the first 7-8 guys are off the board. Rosario has a big bat, but with Posey & Rizzo playing C & 1st, he's now your utility guy (which isn't bad but it prevents you from taking the best available player in the draft if you already have a position filled. You can't go wrong with any of these guys with your 6th pick. I say try and get an idea of what the other guys are keeping, see what players are going to be available and go from there. The safe pick is Cabrera, but Rosario could get you a nice player in return from someone who needs a catcher. And keeping Zimm would allow you to take hitters with your next 4 picks (or 3 hitters and a closer).