Frontier shares everything drivetrain wise with the Xterra....engine, trans, radiator, transfer case, axles...... Being a 2010 you're right on the edge of Nissan having fixed the trans cooler issue. Look for a part number on the top of the radiator and reference google to verify its the updated part. If not, replace radiator with new one, if it is you're good to go. I towed my 4800lb camper 2500 miles through the smokey mnts with my Xterra with no additional trans cooler, and never had any issues. Lots of revs and 8-9 mpg though. People that bypass the radiator based trans cooler in a attempt to fix the possible cross contamination on the cheap using a air to oil add on cooler usually end up with overheated trans fluid. Just keep the stock radiator setup, as it works well. I think the Frontier is rated to two up to 6500lbs, but having experienced my camper, with as much drag as it causes I probably wouldn't go for much over 5,000lbs.
You may experience a annoying rattle, sounds like a heat shield rattle at about 2300-2400 rpm. That is a well known rattle inside the variable length intake manifold. My 2012 had it despite the service bulletin stating it should have been fixed by then. Easy fix, for almost free. Google and you'll find the bulletin.
The rear axle seals are prone to leakage, but aren't that hard to replace despite what you may hear on the internet. Replace the poorly designed axle vent with a hose and filter.
Its a solid truck. I'm at a bit over 90k now and aside from the rattle, i've had zero issues. I plan to keep this truck for another 150k at least, and have no reservations that it wouldn't be able to do that.
I did fluid film almost every square inch of my truck, frame inside and out, inside all the body panels and such. If you're in a rust prone area that would be a good idea, though I do not think these models are particularly rust prone.
I'm pretty sure Frontiers have the same electronic limiter Xterra's do on the throttle. From 0-just under 40mph the throttle is limited to around 65% or so. After that speed it opens all the way, and you can feel the difference. Its irritating to me, and makes the truck feel......"soft" off the line...like you know it has more power, you're just not getting it. This can be undone by all the popular handheld tuners out there for about 300 bucks. Haven't tried it yet, but it's on my to do list for modifications.
Timing chain issues were common on older vehicles, but should be sorted before your truck was produced.