Anyway, it is not possible to derive the public key and the address without using using a computer
It is quite possible to do this with pen and paper.
I don't know the ripdem algorithm, but the sha and key multiplication could be done in a few hours of concentrated work(and a few hours on the next day to check). Nothing you want to do, but otherwise, if you can't trust any of your hardware, it could be the ultima ratio.
No it can't be done manually. Jackjack explained it all in another thread where this came up. Search for it.
Anyway a lot of the heavy weights are in this thread. I would have thought that generating private keys manually might be termed a little extreme.