I pretty much had a feeling that the character was gay from your outline, and also that I noted you didn't explicitly state his lover was a woman. Guess my "gaydar" is working
I don't think you'll find anyone here has a problem with that, and if they do then just ignore them cos they're a moron anyway.
I do think Wing Chun would be a good option for the character, especially given the introduction of his daughter. There are some guys on here who have good knowledge of Wing Chun, so if you wanted more technical advice I'm sure they could be called upon.
This sounds like a really interesting piece of work. Out of curiosity, any chance we will be able to get to see the finished product?