To answer your first question. I'm a fan so far of keystone. I haven't had any issues in mine. We bought a 2016 3290BH last year and for the past year and 2000 miles and a dozen camping trips, it's held up perfect and looks new. My only gripe is the bathroom is a little small, but I figured for weekend trips, I won't complain. Like any trailer, ST tires that come on them are horrible as far as towing, they all sway. If you have the $ or when your tires run out, upgrade the rim/tire to LT and it'll tow like a dream even with the truck you have now. Personal experience says so.
Second thing, please keep in mind weights. Not sure if you're one of those that'll go over the limits, I personally would never. I'm just going to layout the facts, but just know that if you went to the scale your 7500 rating would be less. The truck weight does not include your gear, fuel, etc. Put it on a scale, dumps are usually free. Get the actual weight of your truck. Then, look at the stated curb weight for your truck and subtract the extra from the capacity. example. My dodge 2500 is rated at 2020 for cargo. curb is stated to be 7500. Actual on scale is 7800. Towing/cargo goes down 300 pounds. Now I'm at 1720. Diesel fuel is approx 7.5 pounds/gallon x 35 gallons = 262.5 pounds, subtract again. Trailer tongue states 850 pounds. actual = 1156lbs. with weight distribution (rounding up to 1200 lbs) that puts 800 pounds on truck (400 front axle, 400 rear axle). cargo leftover is now 637.5 pounds Add family to vehicle, snacks, drinks, electronics, etc, you know what your family weighs, in my case, i'll throw in 500 pounds between us, kids, car seats, etc. I basically have no cargo leftover. Towing is now 9000. Subtract my 1900 pounds or so in cargo/trailer tongue, I can now tow 7000 pounds give or take. On the scale, after weight distribution my trailer was 5880 I believe. So I'm in my comfort zone. I have approx 13% towing left. I'd like to be at 20% or greater is the average rule of thumb. My truck pulls very well, it is a diesel. Gas engines would struggle/run high RPMS, I know, I've had one.
Long story short. Keystone is good and for that camper, I would highly recommend a minimum of a 2500 truck for comfort. Gas/diesel is up to you.
Hope this helps!