I can totally understand how you feel RE the paint finish, kind of makes you loose the love for it ! iv been in that place before too.. gotta try see past it tho if you can.
As for the rot on the Sills? not too much hassle for someone to weld those up (or even fit new ones), i dont even jack mine up on these parts, i use the rear beam for the back, and a similar part on the front - hard to explain, id have to get you a picture.
I do have to drive onto a gradual step of bits of wood to get my car high enough to get the jack under tho as the bit i put my jack on at the front is the lowest part under the car almost. (this sounds like jibberish i know lol)
But it saves on any damage to the rust proofing on the underbody of the car which can then lead to rot down the line.. once you get yours sorted id follow this way too, ill try get u a pic
in the mean time try stay positive
