GPA doesn't matter as much as people think. it really comes down to how hard you work and if you're normal/likable.
It depends. As
@FutureDPM123 mentioned, you won't even get approved for clerkship at most good programs if you aren't top half/third of the class. Heck, there are probably a few programs where I wouldn't have been given my first choice month (and therefore would've had a hard time making my clerkships schedule work in the way I wanted it to) even with my pretty good but not elite rank/grades. So GPA matters.
No clerkship = snowball's chance of residency interview/match at most top programs. That student is basically ruled out there unless possibly program spot goes to scramble.
This especially true with likely upcoming residency shortage in a few years if new UTRGV school doesn't create spots (crystal ball = they won't).
After getting clerkship, then no, GPA is not too important... unless perhaps interviewing for programs one didn't clerk/visit.
There is nothing wrong with trying to get some of the more "sleeper" programs that are newer or less popular yet have good volume... but a student sure won't be approved to clerk (therefore won't ever match) at Grant or Inova or Kaiser Oakland or UPMC, etc if they are bottom half of the class.
...for OP, there is nothing wrong with visiting other programs while you're in a city (especially if one of yours is a total dud once you start).
You can try to do that... but as said, also limit it down as much as you can. Pick good clerkships and focus mainly on them. There are just not that many truly good ones in most states/areas.
While in Atlanta, there is no point to see the VA (which is the only other program besides PI, at least back when I did the clerkship). While I was in Detroit, I clerked months at both DMC and StJohn Ascension main a month each but visited Oakwood (Beaumont) and StMary Livonia and Henry Ford Macomb and StJohn Providence in that span too (I was just straight up with the clerkships, I was a pretty strong student and just told the clerkship on arrival I'd be taking X day off to visit another program... since I had found out the day I could meet visit program's director or see director's surgery at the other area programs). I also clerked West Penn but visited UPMC for a half day of director's clinic. In Phila, I clerked Penn Presby month but had planned to see another hospital on one day (it was actually my last clerkship, I knew where I'd match 99%, and I think I just went downtown that day). So, I had 5 clerkships... but I visited 10 (could've been 11) total programs. It didn't matter for me in the end since I'd basically made up my mind where I was going before clerkships even ended, but it was still good to have options and a couple known backups just in case. My interviews at my backups were better received since I'd visited and met the director, although I hadn't done the full month there. So, that's an option too.
Post I'd made is
here on some of the historically strong and higher volume programs. It changes, though... some programs gain/lose key attendings (might leave, some start a fellowship and train fellows instead of residents... big hit to residents there) or the programs sometimes might lose surgery locations (usually due to new program opening at a hospital that was formerly covered by prior program's residents). The programs that are historically strong are almost always your best bet since they have enough attendings/cases depth and enough talented people who care about the program's quality to handle losing a surgeon or two and still be very good. The lesser programs are adequate but don't have that ability, and a lot of them are a turtle on its back and will struggle to get numbers if they lose the director or key RRA surgeon or two (and then there are total crap programs that basically fake their numbers to begin with).