Yeah, glass tanks can be difficult, but all the problems they present are surmountable. Some people even prefer them.
That CHE will heat the entire interior of the tank, but expect it to take longer for the substrate under the hide to warm up, it may take a few hours or so to reach the same temp as the rest of the warm side, but rest assured it will.
That's a lot of bulbs! If it were me, I'd scrap them all and go with one CHE, plugged in 24/7, and running on the thermostat. It's more efficient than incandescent bulbs also so it'll save on the electric bill.
Sounds like your doing well and let us know how the shed goes.