I've been using CA + microballoons for a long time. Sounds similar. With the CA+balloons, the mix gets harder and harder the longer it sets, so rough sanding is easiest at the beginning. Will try your combo too..sounds good!
Solvent glues and CA are pretty caustic. For some parts I use Elmers white glue, which will not ruin paint and cleans with water.
Also, holding parts with your fingers will get old real fast; you are not a clamp. Maybe set your model on a surface propped up however it has to be, then try to come up with some sort of blocking that will hold the part roughly in place without glue. Let gravity be your friend. Then when you finally apply the adhesive (you need less than you think) position the part then block it up for drying.
I use anything for supporting the car and its parts, stacks of old business cards, lego, popsicle sticks held by those alligator-clip "third hand" things; whatever works. Then go have a snack after you're sure the part is in position and not apt to slip or fall.