Good job cleaning the aluminum with the grinder. Only thing is that aluminum begins to oxidize immediately so use muriatic acid to clean it just prior to welding, ditch the alcohol.
TIG on aluminum is tough, but once you get it, it's sweet. If your machine can't run A.C., you're gonna have a tough time, much easier with a.c.. make sure that you have the right tungsten, and "ball" up the tip first (no pointy tip, you want a ball at the tip. If you use a pointy tip you won't be able to control where your arc is going)
Once you draw an arc you want to do a little dance with the torch and filler rod. If you're right handed you're going to move the torch to the left about an 1/8th of an inch and back your filler rod off to the left the same. Then the torch goes right an eighth, the rod comes right and dips into the leading edge of the puddle, then everything goes left again. A little left/right dance, about once a second. One one thousand...so left for half a second and then right for half a second, rod and torch moving in unison.
Hope that helps.