Definitely not too full. You'll have to mess around with the rock for a while to get an arrangement that you like. Be patient. You've got some nicely shaped pieces in there, try and think about how a reef looks (or find some pics online for inspiration). Maybe put the branching pieces up towards the top?
I don't see any problem with the
LR touching the glass as long as the piece in question is stable and has little or no chance of moving if your critters decide to move the sand around etc. I think pieces near the bottom would be fine.