Kieboom is a 40 on speed, 40/45 on fielding, and 60 on arm. Sounds like a corner OF if 3d doesn't work. I wonder is that 40 fielding is as a SS. Raters seem to think he can handle 3d or 2d. The Garcia write up also suggests he may have to move off SS to 2d.
I don't see 2B working well for him. I think 3B is his best bet. The question there is his hands, and when you have a guy who hasn't played much corner IF sometimes the only way to see if he's got the hands for it is to put him there and see what happens.
Haven't seen enough of Garcia to have much of an opinion on him.
He reminds me of Castellanos. We have the time to get him to work on his defense, but if he cant play the defense, his bat is going to push to put him in the lineup ASAP.
The defense rating depends on range. His range is limited.
Not the worst comp. I was in the RF bleachers at an A's game a couple years ago when Castellanos was playing RF. The fans were giving it to him, and some dude was telling him he could play outfield better than Castellanos. After about three innings of it, the response he got was a laughing, but less polite version of "Yeah? How you gonna look hitting third?"
The 1990s version of this was Jeff Kent. He eventually managed 2B adequately, but the point is that when dudes can hit you find a place, even if it looks like Castellanos does in right.