I agree with your sentiments, mostly. Cantrips can most defenitly use some tweaking as they are right now.
Only nitpick to your post is minor illusion. Hate to be the bearer of bad news but what you describe is not how that spell works. You can create sounds or minor inanimate objects. And when I say minor I mean minor. One of the forms given as an example is a small chest. Maybe a small creature could hide behind something the size of a small chest, but medium ones probably cant.... Conjuring a wall could work considering it can be a 4 (or 5, cant recall) foot cube I suppose but the first attack aimed at you would reveal that the wall is an illusion and make the wall transparent. Also if creatures get close to it an succesfull investigation check against your spell DC also reveals it them that it is an illusion. Aside from the fact that you cant make the illusion the shape of a creature, attacking them doesent trigger attacks of opportunity either. Moving outside of engagement range when you were in it does. Its basicly a creature getting off a quick stab before you get out of range because you literally walk out away from combat and let your guard down. Where as disengage is a orderly retreat.
So either you have a very generous DM who wanted to reward out of the box thinking or he doesent know how the spell works either. Both are fine honestly, each dnd party plays the game differently but if Larian want to portray minor illusion accuractly they wont do it the manner that you described. Aside from the wall I suppose, that could be an option but it would only give benefits to the first attack aimed at you.
I havent tried Prestidigitation but its uses are many and very varied. I can understand if Larian cant include all of them.
