I'm not sure about corruption charges w/r/t Ma, but wasn't much of the investigation into WJP last year done illegally? The prosecutor Ma tasked with going after Wang was jailed for wire-tapping. I would imagine that will come back to haunt him.
I doubt if Tsai Ing Wen wins the presidency she will go on a romanization/name changing crusade. She is not nearly as much of a zealot as A-bian, who himself largely went that route only after years of being stymied by the KMT legislature and to distract from all the corruption charges against him. I think we will see a lot of quiet administrative changes done in the name of reform and streamlining that will achieve much of what the name changing campaign sought to do, for example getting rid of the skeleton of the provincial government and references to 台湾省 in addition to superfluous ministries like the Tibetan & Mongolian Affairs Council.
The DPP will not be able to destroy the KMT; only the KMT can do that, and it's doing a damn fine job lately. If Eric Chu is actually able to enact the changes he has come out in favor of, then the KMT will likely make a comeback, but it will aslo be nothing like the party we know today.