My problem now is an extremely sluggish phone. Would this be due to the upgrade (4.4.2) or the root process? Would it make more sense to downgrade or flash a custom ROM?
Root should have no effect on performance at all. Its more likely that there is some data from a previous build causing a process to hang.
I would factory reset and start over clean. Only restore essential data.
You can also use Better Battery Stats. Find it here on xda. Great app for solving battery problems.