Is it possible to change the tempo at a part using a time marker? I know you can change time sig, but I can find an option for tempo.
If you're talking about a track then yes. Right click it then click on....Track information i think or track properties...cant remember exactly but its between those two. Then, at the bottom of the new screen, check "ignore project tempo" or something like this. You can now write your own tempo for that track. Useful for midi drums if you ask me.
To buy:

Line 6 MM4
Voodoo Lab power
Mesa Boogie Single rectifier
Boss TU-3 Done
Shure SM58 Done