The placement of the probed thermometer here is fine, the only probe you don't want on the inside is the probe from the thermostat. Just make sure the probe from the thermometer is sitting directly above your UTH. Your temps seem fine except your surface hot spot where the UTH is, you want this temp around 90-92 degrees.
If you have difficulties maintaining humidity levels, once you get the hot spot up to 90-92, and keep your ambient temps around 77-85 degrees you may find it useful not use the red lamp if you can keep the other temps stable as lamps seem to lower your humidity levels.