Towing 2wd 4cyl 4door non PreRunner questions

I just want to be safe. My truck is odd for around here,being a 2013 2wd,4cylinder,automatic,4door shortbed. And definitely not a PreRunner. Much lower to the ground. I have added the Timbren spring helpers to the rear. The things that look like airbags but are just hollow rubber. They go where the frame stops bolt on. I also added a transmission cooler. And a class 3 hitch.I can't imagine going over 3500 pounds total with the weight of what is in the trailer,the trailer and the stuff in the bed. I think the towing capacity is 350 pounds tongue weight and 3500 towing. But that is just what I have seen posted for the majority of the trucks like mine which did not come with a factory tow package. I just have not seen any others just like mine. My questions are.
1) with my set up is the 350/3500 safe to figure on as a max limit?
2) what are the recommendations as far as using cruise control while towing?
Thanks Randy

 

Wow, I have the same engine/transmission combo in a Prerunner and have done a little towing while helping my son move a couple of times, and absolutely cannot imagine towing the kind of weight you're talking about. The most I towed was probably no more than 1800 lbs, and even then I'd be in 3rd gear much of the time. Is this something you're going to be twins a lot?

 

If you have the 5 lug, you are risking damage to the diff if you go over the 3500lbs too much or for too long

 

Can a mod move this to the "towing section"
I don't think I would ever hit the 3500 pound mark. I just have a small 5x8 trailer but I was thinking of going a little bigger. Maybe 6x10 at the most. I would mostly be carrying old Minibike frames and trikes but literally stuffed to the gill. But even then at say 200 or so pounds even in a bigger trailer I couldn't imagine more than 10@2000 pounds and even if I had 500 pounds of camping stuff I don't think the trailer would weigh 1000. So that is where I am thinking 3500 max.
Why is cruise control not a good idea while towing?

 

I know A UHaul 5X8 trailer weighs over 900 lbs empty. As for using cruise, I've found that the transmission shifts up and down a lot when I'm pulling a trailer. But even not using cruise, if you try to maintain a set speed, the trans is going to shift up and down a lot.