I'm wondering if/when I switch over to fixed, will that mess with the treads ability to displace water? I don't plan on doing much rain riding, but I'd rather be safe than sorry
Interesting you brought this up because I was just talking to my sister the other day about the debate on tread and water displacement on road tires. According to Sheldon Brown, and others, tread is unnecessary on road bike tires because the contact patch of road tires with the road is shaped like a canoe, which is the perfect shape for displacing water.
That said, if it was my bike, I'd check the sides of the tires for any arrows indicating a direction, and head that suggestion. I also don't take/have the time to tinker with stuff, so if I flipped over to fixed gear I'd probably end up leaving it that way for a long time, so I'd dismount the tire and remount to satisfy the directional arrow. Or just buy a cheap, no tread tire off craigslist and live free from all that hassle.
P.S. I like your bike - I'd like to read more details about it...