Related ideas:
-Explosive Guard Posts, Proximity mines, etc
The ESG in OP2 just plain looks wierd. I'm sure I'm not the only one who thinks this. It doesn't even look like a weapon. This idea would affect gameplay in no way whatsoever - but I want a cooler looking ESG turret! The mines too - the little blinky things are just kinda wierd looking, and don't resemble mines at all.
Now for the part that effects gameplay - the fact that it makes a solid block of mines is kinda wierd too. Suppose it fired fewer mines, that scattered out randomly over a larger area. Also they might last longer, and you might lower the ROF a bit. I hate how the ESG has to be on-site to keep a minefield in place, making removing said minefield a simple matter - kill the ESG, and you're free to go. Perhaps make a way to kill the mines, as well, with a minesweeper unit/weapon?