Lat Angel Rin - Problems

Problems:
1. The shorts keeps on moving and bending and showing her skin.
2. Her shoes and legs keeps on flickering in random directions throughout dances, even though it doesn't clearly show here.
3. Her elbows continue pass through her sleeves.
4. Although this is an unnecessary complaint, her vest has no physics.
5. Although this is an unnecessary complaint, her wings have no physics.

Alright, so, I'm close to finishing Angel!Rin, but I keep on running into problems that I just can't seem to fix. The first three problems listed above are the ones that bother me very much, and this is the SIXTH model of Angel Rin I had remade all over again from the very start! I keep on running into the same problems over and over and over and I have SIXTEEN edits of Angel!Rin models I had made when I had continuously tried to fix them.

So, I finally decided to come ask for some help. I was wondering if somebody can fix at least the first three problems I noted; it would be much appreciated if they cuold also give the wings and/or vest physics also, but it's completely find not to.

Anyway, if anybody would like to get a look at the model, then just tell me through comment or note and I'll note you back to link to this model. (Only this one model; not the sixteen that I had made in attempts to fix it myself.)

Credits:
Piron Lat Base - mersan-sama
Lat Rin Hair - Lat
Flower - IdolM@str
Heart Necklace - IdolM@str
Vest - IdolM@str
Cute Band - MMDFakewings18
Sleeves - MMDFakewings18
Shorts - IdolM@str
Boots - IdolM@str
Wings- MMDFakewings18

I edited this on a program called Photoshop made with a program called MikuMikuDance and I really need help with this.