Some random thoughts regarding lav mics:
#2) A piece of 3M Transpore surgical tape over the head of the mic actually works as a decent windscreen.
A quick guerilla solution for when you're on-the-go.
#3) Hiding the wire on the inside of the shirt can be done by lining the wire along the natural line below a person's pectoral muscles (the breast area), then bringing the wire down the side of the body (using 3M Transpore surgical tape as needed), then tucking everything behind the body - usually against the pant's back lining - neatly.
#4) Sennheiser G3's sometimes sound fuzzy.
Try as you might, they just frequently RF spike.
It's in their nature.
#5) The smaller the lav mic, the easier it is to hide, the easier it is to reduce rubbing.
If you're forced to work with the stock Sennheiser ME2 microphone, although they sound fine, this will be the struggle.
#6) The best place for a microphone is within the hollow section of a person's upper torso.