I would have 90'd from the building rather than 45'd....personal preference really....less line hanging in the open. also don't see a point in rigid on the SL.
are you saying the combustion condensate was internally trapped, or the coil is internally trapped?
I also would have shortened the 'T' and capped it on the drain line. shouldn't be any issues unless static is high.
also snow legs on the furnace to keep the metal off the concrete (if you have the room), and the same on cond. keeps both from rusting early, and allows cond. to drain without getting crap plugging up the drains.