i cant tell you how many times i would have been able to use your epoxy in clear over the past 18 years. i actually did something recently where i ended up taking a bar top type 100% solids epoxy and just adding 10% acetone to it then shot it on with my sata 2.5 poly primer gun. ended up working out awesome. comes out cloudy from the air entrapment but after about 2 min on the panel it all goes away. i was originally worried about trapping the acetone but the epoxy stays wet for about 5-6 hours so there was plenty of time for that to escape.
you can use a heat gun. i think the torch works better though. for sanding the epoxy it depends on what your trying to do. if your epoxy isnt smooth and hasnt self leveled then you need to sand it down with 80-150 grit. you will usually have to work the epoxy down quite a bit to get it flat. smooth the 80g scratches out a little with some 220 then you can just clear over that.