>>What you want to know is the snakes temperature.
Where the snakes temperature is important - just as important is the ambient temperatures. If the ambient temps are wrong, then a snake cannot metabolize correctly and can easily get sick. Yes, the snakes temp can be fine, but the ambient temps can be off enough to cause a respitory infection.
>>BTW, the temps and equipment you mention all point to correct temps (except of course the misplaced thermometer).
Temps at 70 degrees are not correct for ball pythons. The setup does not have an accurate enough thermostat to say whether the correct temperatures are being maintained.
>>Reptibark is terrible bedding, not very absorbent and probably awfully uncomfortable to lay on. Breeders (ie those with the most valuable animals) use sifted pine shavings, shredded aspen or paper. I use pine and when humidity is an issue then I just add water to the pine. Works great.
LOL - Reptibark is good bedding, very absorbant and close to what snakes naturally lay on. Big breeders keep their snakes in tubs and racks and don't have the same issues with heat loss that you have in glass aquarium set ups. Reptibark is much better at insulating your aquarium type set up than paper or aspen. Cypress mulch (which big breeders also use and would have the same look and feel as reptibark) could also be used and would be a good insulator too.
-----
Tosha 
8.10.0 Ball Python (Harry and Fluffy and currently un-named)
0.2.0 Feline (Pippen and Pandora)
0.0.1 Dessert Tortoise (Pope)
7.9.5 Fish (1,2,3,4...)
0.0.1 Frog rescued from pool skimmer
0.0.2 Lizards rescued from pool skimmer