Ooops, didn't notice this thread kicking around. The lock: Yeah, it'll keep an honest man honest, but if they want it bad enough, nothing in this world is safe.
The screws/hardware: They're just lightweight hardware kits from Home Depot, the same hasp you'd put on a small cabinet. I just had to cut out the cap piece to accommodate the "hoop" end that the hasp goes over to lock the cap on. I tried to find the shortest screws I could since they protrude into the inside of the tube. I had to mount a piece of slim wood into the inside to suck up the last part of the screw threads and keep them from scraping on my bows going in and out.
Heat: The bane of any tradbow, especially in the south. I mentioned it above, but I usually only use the tube to get from point A to point B. Long term storage isn't really necessary for me most of the time. On the odd chance that the bow is in there for a while, I park under a shady tree and add a few minutes walk to my destination. The light tan paint is by design, to reflect some of the light and heat back away; black would have looked cool, but way to heat absorbing. I always put my longbow in a sock before it goes into the tube for added protection. The hose clamps are bolted to the rear of the truck bed, but should something ridiculous happen that case can take a beating and the bow (in its bowsock) will likely fair well. As I mentioned above, a thermal blanket around the bow may help as well, and If the need presents itself I am prepared to invest the $20 (?) and couple hours to:
1) create a thermal blanket sock for the bow to go in before it goes in the tube
2) affix camo netting to the top of the tub to deflect direct sunlight.
Perfect it is not. However, for the time/money invested, I no longer fear my door slamming on my delicate tips of my 68" longbow, and since most of my truck travel shooting isn't in the summer I haven't had any issues yet, though we're only talking a year of use so far.