Avoid S-Trap Sink Plumbing
Since you framed the wall behind the in-concrete drain rough-in, you will use an S-trap from the bowl to the drain on the floor. Had you really wanted to use a P-trap, you would have framed the wall directly over the rough-in, used a P-trap into the wall, then an elbow down to the rough-in in the floor.
If you really want to use a P-trap then you'll need to move your wall. Since that does seem quite rather impractical (and probably makes the toilet rough-in unusably close to the wall), just stick with the S-trap. Functionally, an S- &amp; P-trap work the same. I'm not aware of any additional clogging issues with an S-trap over a P (I have all S in my house and have very minimal clogging issues, especially since the long-haired daughter moved out on her own), so there's nothing to worry about there.
Dropping Placing a vanity over the pipe in the floor really isn't that difficult in comparison to pushing it up against the wall. You have to measure carefully in each case to get the hole cut (in the floor or the back, as appropriate) in the proper place, but you just make the hole a bit oversized and it's not difficult in either case. There's no requirement that the pipe be perfectly centered for either installation method.