Never reuse yeast if you have fining droppen on top of a yeast cake. You can rack and then to finings, but check to see the temp needed for the reaction to happen. Some, like isinglass, need very low temps to bond to the excess protein and lipids to get the clarity your looking for.
I do all my fermenting in converted chest freezers. If you have a thermowell port added to the bucket, put it there. Next would be inside a jacket around the bucket. You want the probe to tell you the temp of the wort fermenting, not the ambient air. Also, you should put a fan inside the...