This is akin to the first dent you get on a new car. You dread it until it happens. After that you accept that something you use frequently is going to get a little wear and tear.
Your dings are barely visible. (I understand, you'll always know it's there.) They're learning moments. If either of them really bother you, a good repair shop can try to steam them out and then repair the finishes. (See StewMac video.) But I'd recommend just fix the finishes.
I don't understand why your strings broke. Unless you way over-tightened them.
I've only had one string break for any other reason. (It was an early Aquila Red.) And I use very thin fluorocarbons.
It's easy to be an octave high if you don't have a reference sound.
If you have more than one uke, use the one you're not restringing to get you in the neighborhood of being in tune. Then use your tuner to fine tune. Or use an online tuner with a tone to provide a target.
I tighten the A-string (and high-g) slowly. As it gets taut, I let it rest and stretch while I tune the other strings. Then tighten some more. Until I get there.
I will deliberately over-tighten a step so that the string will stretch and settle faster overnight. To A#.
If you use a low tack tape to protect your top, do not leave it on more than a few minutes. Especially masking tape. It will leave an adhesive residue. I don't know if they even sell it anymore, but Drafting Tape was the lower tack version of masking tape. Your tape needs to be fresh as well.
If you worry about it in the future, you can apply a small strip of clear plastic below your bridge. Like a piece of a phone screen protector. LFdM tenors do this on their tenors. It may affect the finish, so once it's on, don't mess with it. Pickguards can be removed by a luthier or repair tech, I don't know about screen protector materials.
Sorry it happened. It's a bummer.