couple of comments to make.
Blazing Salvo seems nice, but it is inherently flawed. Firstly it cannot be aimed directly at players, in a situation where u need that burn spell to win it can suck. Secondly, and most importantly i believe, it has no guarantee that it will do what you want. It is never certain to kill a creature(unless they on 5 or less life) and it is never certain to do your opponent damage. However it is good, being 3 or 5 damage for 1 mana, however for the reasons i give above I hasten to use it.
Mages contest IS good. The way to play it is to treat is as a burn spell. In most situations the following happens. They play spell(say Wrath of God for example). You reply with a contest, bidding the initial 1 life. Usually they will then bid 2 life, and then you will bid 3 life. Now your opponent is faced with two choices. He could let you win the contest, and make u lose 3 life, and then face the beatdown of your creatures. Alternatively he could bid 4 life, and then maybe get his wrath to resolve, but put him 4 points of life closer to death. Therefore the way to use mages contest is too save for the big game breakers like Wrath, Opposition etc, and then make your opponent really consider how far he can go, and thus you can normally save a bad situation for yourself, or make a bad situation considerably worse by losing your opponent some life
BTW uwr trenches kicks ass. Will post my decklist soon, when I fully tweaked it
Ciao for now
Michael