I had a similar ride in 2006, a trek 1200 with the tiagara stuff/105 rear derailleur. I also got interested in SS/FG riding, but found that it really makes more sense to use an old 10 speed or 12 speed bike with horizontal dropouts to do it. So I never converted the trek, I just picked up an old steel frame and did a conversion.

After about 1 year of it, I found that I liked it just fine...no real worries, but I now ride with gears again and probably won't go back.

About 97% of the time I liked SS/FG, but man when the wind is really whipping against you or if you are just plain wore-out, I hate SS/FG. I rode a lower gear (usually between 62-70 gear inches) and was/am pretty fit, but still didn't like that aspect.

I find that I can carry more weight on my ride now too, and I just have fewer reasons to second-guess riding....I find having fenders helps with my attitude toward riding too. ....just my 2 cents. For a short commute (7 miles or less) you probably would be just fine.