Mines do provide chance to ignite already. Normally you'll get about 2 components or so ignited with 5 stacks of fire. Incendiary I've noticed does add to this.
Yeah if you want to really do some fun stuff with mines then I refer to my Sky Torpedo posts. That is literally a huge propelled mine.
The ammo and usage of mines is fine as is. You don't really want to mess with them. I'd personally like them to return to the dmg levels they had in dev app before release but you would be seeing ships wreaked much quicker.
Lot of people have a concept of mines being defensive weapons only. Backs of squids or galleons being prime locations. I thought that as well until I played around with Munkers, initially just for fun. Mines are domination weapons. All you need is 1, 2 is better, and you can keep an enemy team locked down. I've outlasted 3 v 1 engagements because my miners placed the mines perfectly and we locked down all 3 ships. The amount of dmg being spread around was enough to force them off their attack and buy my allies time to come back in. When they did, they had easy times cleaning up the crippled ships.
Mines however, don't have a ton of killing power. It takes a few to be able to crack hulls. Which is why you need your ally to be able to kill for you.