It sounds like you like a fairly minimal bike. Honestly fixed gears aren't bad for commuting, depending on how far you go.
I ride 10 miles (one way) to work each day on a fixed gear that was <$300.
And, despite being fairly new to biking, I've ridden 25 miles or so at once very comfortably and am planning a metric century in the near future.
With your other questions/statements, it just depends what you like and what you need on your bike. I personally don't have any racks. I have two small clip-on lights that come off when I'm riding during the day. And a YNOT saddle roll. I've ridden in the rain and the cold and done fine with that so far. But others would feel better with fenders, a rack, and a water bottle. It's all preference, but you don't NEED it.