I can think of a lot of mission uses for mines, and they would not need to have a very complex behaviour.
1) Simple contact trigger mines. Lay them in fields to set up defensive fields to protect bases, jump nodes or similar. Missions would be written to deploy or lay the last 'area' to fill in before incoming ships arrive. There would need to be a player de[ployable one as well as a fred placed one. Ideally, you would want them to be relatively powerful and with enough seperation between them to get a good coverage. Chain reaction of minefields is not something that needs to be prevented..... it is a REAL issue if you lay your mines too close together. They would be used for anti-capship defending...not anti-fighter.
2) Proximnity mines. These would have a much lower explosive yield, and could be used either as a defense weapon to seed fields, or as an alternative to 'discourage' enemy fighters from flying up behind you!
In case 2, the AI would need to be able to make some use of them, and would need to think of them as an untargetted rear firing missile. Which, from the above, seems to be the most likely case.
In both types of mines, you would want to have either an EMP type of charge designed to fry shields, or a simple explosive type to damage hulls. Switch loadouts mid mission to get a variety!
The option to self destruct all th mines you laid yourself would also be a good idea. I can imagine the pleasure of laying a nice field of mines and seing that lovely big enemy vessel warping in and running smack into your field of mines ....and hitting the 'detonate' button.
Mines, by definition, are used as a defensive weapon to control and restrict a battlefield. You can mix them up with sentry guns to create choke points and control the attacking forces and bring them into the killing zones. Enemy ships should have a chance of detecting these things and reacting, with some degree of awareness of the danger. If you want ships to hurl themselves onto them in a suicidal way, then I am sure the FRED elements can make them do something stupid like that

Detection should only be possible at short range though. Otherwise the things have no purpose.