As a minimum front wheels should be balanced to reduce bouncing.
Tire: 5.70-8 LR (Load Range) B, Carlisle Sport Trail. See attached Carlisle chart for more tire information. No need for higher LR. Note speed range in Carlisle chart. Same for Sport Trail and USA Trail, 62 mph. If balanced then it seem to me both types of tires are fine. In the past I have used Kenda Loadstar K353 with no difficulties.
A wheel is a tire, rim, valve stem, hubcap (if used) and inner tube (if used).
There are lots of "How to balance wheels" on Youtube. This is an excellent place to check out. I thought balancing motorcycle tires the best videos to watch.
The initial front tire balance method I used was leaving the wheel on the KM spindle and losing the retaining nut until the wheel rotates freely. I later used another method because of the construction of the KM rim (see pictures 1-4). Freely rotating is obtained when gently spinning the wheel in one direction and watching the wheel stop and then rotate in the opposite direction. This rotation action continues until the wheel stops. To mark the stop location, I matched the valve stem with clock number locations. In my case the stopping location was always between 9 and 10 o'clock.
Stick-on, clip-on or balancing beads wheel weights. The King Midget's 8 inch rim small size and construction presents problems. Due to the brake drum and minual space on the rim's face I found stick-on weights very difficult to use. Clip-on weights can be used on both sides of the rim. However, clip-on weights do have a problem. Which is the shape of the weight used in the clip-on. The problem with clip-on is they are for a rim larger than 8 inches. Luckily the smaller ounce weights work. In my case one rim took three 1oz. clip-on weights and the other rim was three 0.75 oz. weights. I only balanced the front and not back tires.
Bead balancing seemed to me to be the best idea. Easy to install, works with tubeless or inner tubes and found a vendor (scroll down to see advertisement) who had beads for a 5.70-8 tire. However, I didn't use them. Checking Youtube videos I learned some people like them and some didn't. And there was a third group that found as they were driving the beads were sporadically good or bad.
Carlise's chart of tire information.
Vendor available Tire Balancing Beads