Your first attempt at making a sneaker is actually quite good. However you need to take into account that you will also need 300% in your chosen weapon/combat skill to be able to use your weapon correctly due to your 1 strength. Of course this is only accountable if you choose to do aimed shots which I argue you should do. The one hander trait assumes it will help but in my opinion it really only assists when using a gauss pistol since it has a larger range than a .223 pistol, therefore needing a trait such as that to maintain accuracy more than just the 300% weapon skill. Also I agree with Rinzler in that, while you do need a good perception for the scouting purpose of a sneak, a really high perception at the expense of luck is not something you should do. Luck 10 is a must; 8 perception is alright to have considering it is still a good sight range including the fact that a cigarette increases this to 9 which is enough for your standard .223 sneaker. Having said all that, everything else is pretty much spot on. My only final comment is that you wont really need that 2nd lifegiver if you choose to play a .223 sneak as silent death would be a more preferable perk to choose.
As for your question relating how to get caps and best way to level, all I can offer is to just level through caravans. It takes a good amount of time but if you are dedicated to playing a sneak and you are dedicated to learning how to be one effectively, then your hard work will not go unrecognised. Trust me, sneaks are amazing fun once you get to grips with them.
EDIT: You can also craft weapons, for example the .223 pistols, and sell off the disregarded ones, ie: non statted and terrible statted ones. You will mainly want ones with advanced or unique prefixes so sell other ones for caps. Of course this can be generalised to any weapon that you choose.