[Suicide Junkie]

Mounts do affect tractor/repulsors.

For tractor beams it is pretty useless, since the effect is limited to the range of your beam.
For repulsor beams, a Massive Base Mount repulsor beam can throw ships all the way to the edge of the combat map.

12) Repairs don't have any explicit costs, but you do have to pay maintenance while the repairs are conducted.
It is possible to repair ships while they are mothballed, but you will lose any experience they have.