1. Flame particles don't depends of reactor max heat. It's strange to see flame on 10 000 heat level when max heat level is more then 100 000.
2. Heat level stucks on specific reactor configs (requires to heat up reactor to 200+ heat level):
Reactor heat vent can lower heat level to 4 without heat exchanger, but can't with it.
Console output:
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:06 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:74
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:141
2012-09-08 15:28:07 [INFO] [STDOUT] Reactor heat:74
Heat exchanger damage bar flickers like crazy.
3. Don't know is it bug or intended. Reactor tick rate is 1 tick. Uranium cell is consumed in less then 10 minutes.