If people want him to line up at KR/PR/RB/WR, then he's going to see a lot of plays. More plays = more chance of injury. Not to mention that Harvin has been injured every year of college ball. Whether its was his left ankle, or his right ankle or his right heel. He's got issues.. And, the last I looked, a WR/RB/KR/PR relies tremendously on his feet and legs.
Personally, Harvin's durability is the only question I have about him. I admit it. But even given his injuries (...and a couple of times, I think the UF staff held him out of games that he could have played in), he still managed to average 10 touches/game in the best defensive conference in the country. Teams will have to decide if Harvin is brittle or if he's just been unlucky.
And, the last I looked, he looked pretty fast in the BCS Championship Game despite playing on a broken foot.
Teams have more than ONE kick returner and more than ONE punt returner. What evidence do you have that Harvin can return anything other than his returning punts as a junior in high school?
Brandon James returns probably 90% of kicks. If he doesn't return the kick, it usually means either the game is out of reach, or the other team did a great job of kicking away from him.
Given Harvin's speed, ability to change direction quickly, the fact that he gets to full speed very quickly, and his ability to make people miss in tight spaces, I think he would probably be a very effective kick returner.
Why didn't they ask him to do it? Lining up in the back field, he also has to make a pre-snap read to ensure that there isn't a blitzer he needs to pick up. If he can't do that, then he'll get a QB killed.
Different offensive philosophy. Florida rarely asks RBs to stay in and help pass block - in most cases because guys like Rainey and Demps are too small to do it effectively. Instead, when UF reads blitz, it's up to Tebow AND the RB to read it and for the RB to get into the flat and make himself available quickly. This is why Florida completes so many passes behind the LOS and why the YAC for RBs is usually pretty high.
Personally, I think he's not worth anything but a late 2nd and that is only if he's 100% healthy.
As I said - it depends. If you think he's fragile and have questions about his ability to adapt to a pro-style offense, then I can see your point of view. But then again, I could see a team looking at his downside, and still deciding that they'll roll the dice with a fairly high pick because they view him as a Steve Smith-type threat.