Justins MINES 101:
Your minelayer ===> FrigateNephilUtility5
Ability to deploy mine ====> AbilityDeployMine
THe actual mine ===> FrigateNephilMine
Ability to Phase cloak and cause the explosion ====> AbilityPhaseCloakNephil2
So how does it work:
In order to simplify to the maximum, Ie not having to touch string files and all. I would recommend you simply copy-paste the 2 ability and 4 buff files straight into the gameinfo folder your working on. Then open your gameInfo and Find the PlayerPhase (since you dont have Nephil) entity, open it with Wordpad, notepad ++ and under the frigate tab, add the ship FrigateNephilUtility5 (of course respecting the style of the ships on top (Ie capital letters, spaces,etc..)).
Once that is done, open up the FrigateNephilUtility5 file and any other FrigatePhase vessel entity file and change the IDS String Description and name (should be one fo the first top rows) into that of a FrigatePhaseLight for example (copy-paste the IDS string of the FrigatePhaseLight into the FrigateNephilUtility5). That way, the vessel now uses the lights description and name but allows you not to go play in stirng files.
You may now paste the FrigateNephilUtility5 into your gameinfo folder.
For the FrigateMine, if my memory serves me right, all you will need to do is change the MeshName (bottom of the entity page) which is currently on a homemade entity and replace it with an entity of your own (if you dont have any, just once again, copy-paste the mesh name of another vessel into this slow)!
That done you may paste, the FrigateNephilMine into your gameinfo folder.
Now open up the game as Phase and you should be able to 1) Create the minelayer
2) Once the minelayer is created, he will have the missile batterie ability (I'm gonna change all names of remaining ships and abilities today/tomorrow). Click it, and if all the modifications have been done well, A mine will pop up!
Now the mine, you can either manually activate it by clicking on its phase cloak ability, or let anyone fire at it and it will self trigger the moment it get hits. BE AWARE IT AFFECTS EVERYONE IN RADIUS (Friend Foes)!! AND DOES A HUGGGGGGGGGGGGE BOOM (expect it to kill ALL within radius). Fortunately, as long as you have other ships in the grav well, spawned entities (the Mines) are the comps least priority 
Hope it helped!