Hello everyone. I hoping for help with my install questions for a unique situation because of the radiant heat system that I installed.

Background: I'm installing 600 sq ft in the lower level of my house (below grade daylight basement). I installed a hot water tube radiant system over the concrete slab.
Product: Strand woven bamboo 3.5" x 6' x 3/8" - Manufacturer says it can be floated, glued or stapled
Subfloor: This is where it gets tricky...I installed dricore over the concrete slab (secured to the slab), a layer of radiant reflective material, and then strips of ~3/4" OSB to create small tracks for the tubing to run in between. The OSB was screwed down to the dricore and then we ran tubing with aluminum panels to help spread out the heat. I'll try to post a picture of my actual project but it looks a lot like this : http://www.radiantcompany.com/details/suspendedonslab.shtml
Questions:
1. I've read that I should use cleats because the strand bamboo is so hard the staples won't go through. But at only 3/8" thick, a cleat seems like it would split the tongue. Which would be better?
2. An installer came over to give me a quote and he suggested gluing in between the tubing tracks and nailing with staples. I've never heard of doing both so I didn't know if that would be a good idea.
3. I have a few high and low spots. I'm going to sand down the high spots but I'm not sure what to do with the low spots. I can't pour any kind of self leveler but I've heard that I could potentially use craft paper to build up spots? Any other thoughts of what to do?

Any help would be really appreciated.
Billy