I use regular dish soap to wash my apples and other hard produce, yes. Works a treat, but a dedicated fruit/vegetable wash (“Fit” is an example brand in the US) works too. It may leave fewer deposits/less residue, no idea, I haven’t looked up any papers on it. The main reason I started was even rinsing my apples with water alone, I’d notice a chemical taste on the skins which is very similar to how the produce stands at the supermarket smell. Washing with soap gets rid of it, as long as I make sure to get the crevices at the “poles” of the apple.
Most don’t, but some inevitably do. The FDA actually has non zero limits for things like poop, bug bits, etc. For example frozen broccoli is allowed to have 60 aphids, thrips or mites (small bugs) per 100 grams. Bay leaves are allowed to have up to 1mg of poop per pound, etc.
While you may not do so intentionally, I can assure you that you do, in fact, eat a lot of bugs. In fact, there are countless standards on how much bug can be in your common foods. The amount is never zero.
I have a (little) garden with fruit and vegetables and only a few have bugs inside, like other commenters said when they have bugs they also have a hole so they become inedible before I pick them. I don’t use pesticides and sometimes I find an ant or a worm, mostly inside figs, apples and pears, and when there are wasps inside you can spot them when the fruit is still on the tree and leave them alone!