Regarding power drain, the Probe didn't drain power from humans. So simply use a UT powered by the same sort of processes that run within the human body.
That's a classic and pretty idiotic scifi cliche, really - that technology stops working, but somehow humans don't stop working. Let's face it: we are technology, too. We run on the very same processes that fire up our mobile phones or automobiles or submachine guns. If the alien entity of the week jams those technologies, odds are that we will perish in horrible pain as well.
Regardless, I'd think the UT was already doing its automatic best at translating the Probe's rantings. It just wasn't having much success. We could speculate that most of the alien languages encountered by our heroes are relatively easy to decipher because they follow the same sort of patterns, inherent in the humanoid psyche and brain structure that is nearly identical across the galaxy. Or we could speculate that the UT is always slow in catching up with new languages, and that it only seems to be so fast and successful in standard ship-to-ship encounters with new aliens because standard ship-to-ship encounters involve the polite exchange of helpful data bursts between the respective computers before communications begin. The probe simply didn't send such a burst to the Federation UTs.