I’ve started doing that with mine what the sun doesn’t scorch is usually chewed on by bugs or rabbits if I leave it to color up. Not sure I’ll grow more than a couple plants next year. I might try growing a different sweet pepper or even baby bells since they are supposed to produce better.
I would send off a soil yes before adding amendments. You should be able to send one off via your county extension office. I’m sure other places do it but it’s easy and cheap to send it off there. When you buy seeds try looking for zucchini varieties that say compact or container those should...