ohhh pretty

black too? going to have to post up a pic of yours on the trail

Now, as to the seat post issue, If you are having to clamp down that hard it's not the actual clamp that's the issue as the frame or seat post. Either the frame was milled to big or the seat post is too small. You should never have to apply more than moderate pressure to the joint with the clamp if the post and frame are sized correctly. take it back to the shop and have a chat. If they keep pushing a clamp issue then go else where. Trek has amazing warr and service and will have no problems fixing which ever the issue is. Have it Mic-ed to see if ever thing is in spec.
As to the ghost shifting, is there a certain thing or time that it happens? Can you recreate the issue repeatedly? If so, post up and/or bring to the shop.. If it's very intermittent then try lubing the cables with a dry chain lube or get some "tri-Flow" oil (small bottle with little straw) and very lightly lube the cables like 1 inch of the side of the outer housing. run the shifter through all the gears and dry off all excess with a rag (NOT paper towel!!)
Could be a kinked cable also or a broken or dislodged wire on the cable.