I use 115 Fov. I went from 90 (newbie) to 110, to 120 and to 115. But i havent played tribes in like a year and only opened it a couple times.
The issue of "owning" on duel servers is a bit touchy. Some people believe that winning is what determines whos better, although it does, it its also dependant on how you duel aswell. It also depends what you play, i play HO (heavy offense) on CTF, so there really is no point for me to be a great dueler when all i do is rape, clear, and cluster. Natrualy, a LD (light defense) player would own me in duel since they are more acustomed to it and need to be good at it.
There are a couple things i will not do, nor stand for on a duel server. They are kamikazi mine discing, cg whores, shielding, and sniping.
And about mine discing. It all depends how you do it. If you go for ranged mine discs then its fine. Things like a 15+ foot MA MD take skill, and i would never complain if someone killed me in that way. But if they sit and hover waiting for me to land and mine disc, or go for almost point black mine discs that would normaly kill them if it wasnt on duel mod, then i get a bit pissed.
Good way to shut down the hover mine discsers is just to shoot em before they shoot, so they kill themseves and you just say "Mines have been cleared." "Thanks." And they usualy will get the hint and stop.
Those kamikazi mine discers cant really be helped, u just gotta keep a range between yourself and them so they cant do it without killing themself before you.