Hey Robbo.
The good news is you can set this one up however you like. if you want lower action, its not too hard to set it up that way, but probably concentrate on building it first.
As its a bolt on neck, I would string up the high and low E strings and centre the neck before drilling the neck bolts. rather than putting the bushings in for the stoptail (you want to finish the body first) get some rubber tubing to hold the posts in place and put the stoptail on when doing the mock string up. Alternatively, you can finish the body and neck first then worry about drilling the neck holes when the bushings are in place.
The mock build is just to check to see if you have all the essentially bits and bobs. and make sure everything fits.
If you intend to do any modifications to the kit, my suggestion is to do that before finishing the body and neck.
Good luck mate, good to have you with us
I'd be surprised if the fret markers wouldn't be plastic inlays. They shouldn't wear off.
Sometimes the frets on the kit may need a bit of work, just use a stanley knife blade as a fret rocker to check for any high or low spots.