My one question is this, is a skinny string the same as a regular Flemish twist, just with fewer strands and larger padded tips?
Similar build, just more complicated. Low strand count strings stretch/creep more. How much more depends on the material, draw weight, how many strands, etc. You also have to build up the nock point to get a decent nock fit. You can pad out under the serving, double serve, or build up the nock point.
Ive read somewhere that people pad their string tips with a different material than the string, say a D10 with B50 tips. Is this difficult?
It's not hard at all. I use B-55, but not to save money. Even with the most expensive material, padding the loops costs maybe a penny per string. I like B-55 because it seems to make a quieter string.
I strongly suggest building a string board that goes by string length, not bow length. Depending on the make, a bow marked 64" may need a string anywhere from 58" to 62.5".
Learning to make the string properly will make more of a difference than whether it's "skinny" or not.