Is it possible to exchange FSC1 and FSC2 from Swisscex, without transfer to exchanging site 
It is not. FSC2 is not listed on Swisscex. Currently the official exchange site is the only way to do it.
We're looking at getting FSC2 listed on bittrex next week so you could exchange FSC for LTC on Swisscex then buy FSC2 on Bittrex next week.