I would definitely not take a gap year if I were you, especially not for raising your already-close-to-the-ceiling GPA at a top 10 school. If you want to take a gap year for a different reason, then you should. If you don't want to take a gap year, then just don't- you don't have to. Do you know what you'd want to do during that year, and where you'd want to to it? You already have a great application for top programs. If you take a gap year, you're going to have to find something to do that'll only make your application better, but if you're ready and want to apply now and go straight through, then do it!
I really don't think your B's in upper-level biology courses at a top 10 school are 'red flags', or that anyone would say "Whoah, their GPA 'dropped' from 3.9 to 3.8." Maybe I'm wrong though, and the sdn peeps on here that have actually been on the other side of admissions can chime in. 3.9 and 3.8 sound the same to me- they are both above the bar and excellent. Plus, what if you get two more Bs your senior year? You can't just assume it's all uphill from here. If you play your cards right, though, you could have an acceptance at a top program before your next semester grades are even out (still keep your grades up though).
I think the reason you haven't gotten a straight answer for your clinical experience is that there's no way to tell by just giving your number of hours. Your amount of hours could be enough if your descriptions of the experiences show that they were enough to get you to make an informed decision about pursuing medicine.
Based on your program interests, I had what you would consider a very successful app cycle. Even without all the details of your app, to me, your app sounds like it could potentially be more competitive than mine was- and that's with me including gap year activities. Of course, you do still have to actually put together an interesting and compelling app, and interview well, but... you're on the right track. If you need some more time to think about taking time off, don't let up on your applications for this cycle while you think. If you decide to apply now, having everything in as early as possible will only better your chances at your top programs.