1) Mecsoft has a support forum - linky - http://www.mecsoft.com/cgi/teemz/tee...?board=_master
2) I do not have VisTurn but am VM user and I will bet that you can reverse your axis +/- inside the post processor.
3) On my CNC lathe going right IS + and left IS -
4) Posting this Q on the forum linked in 1) will get you an answer today if you still need help you can also email firstname.lastname@example.org or talk directly to tech by phone. If your software is legal they will look after you immediately.