Since no one else mentioned it, the only way to 'lower' pads in this type of brake is adjusting the pad post length. Push them in. This pushes the caliper farther from the rim, and lowers the position slightly. Readjust the other things like straddle wire as necessary.
You want the brakes to hit the rims at as close to perpendicular as possible. Angled down is to be avoided.
Looks kind of borderline to me, but maybe worth a try. Personally I'd look at a different caliper with an adjustable slot location. As has been noted, there are other brakes. Dia Compe 988 and the new version 980 for example.
There's some chance you may be stuck with 27.
Miyata and Univega typically had their posts in a sort of neutral position, and you could go from 700 to 27 pretty easily. That Trek looks more biased to 27.