Thanks for pointing out that issue, stations that are heavily armed and have tons of shielding shouldn\'t be a part of a battle unless the battle actually occurs next to them. We can make carrier ships, so I see no reason to have a station enter a battle unless that station is being attacked. Speed caps on stations make a lot of sense.
Tugging should also be capped out, as in a tractor beam can only pull a station at a maximum speed, no matter how many tractor blocks you have. Mass could factor into it still, so a station with 1k mass would need 10 tractor blocks to move it at a rate of 1 km an hour. A station with 2k mass would need double the tractor beams to move it at 1 km an hour.
This will make moving stations a serious effort.
I support forcing stations to power down shields while moving, whether being tugged or using engines.
Edit:
Should Tug Ships be required to take down shields to use their tractor beams as well?