I love the rage when something counter alllied stuff, and they cannot just chill and camp on VPs to win, so funny every time 
Easy mode with brits is ending, face that, Lelic took Your money at first, now they will balance it 
Funny how you mention camping the VPs, thats generally a well used german tactic that happens almost everygame.
Playing Brits is far from an easy win. It might've been easy win in the early stages of the alpha, but now it is a micro heavy and difficult faction to play, but rewards you when you get the hang of it. You should try playing them against an Axis player who knows what he is doing. You struggle the entire game until late game, where if your unit preservation is good, you'll be able to keep up fairly well.
The ISG is way too powered at the time being. As Alladin said, it's a very low risk extremely high reward cheap unit, that can sit half the map away and reduce every faction to rubble. I tried stealing two ISGs once; they REKT'ed the opposing team something fierce. The fact that this hasn't been hot-fixed is a mystery and not very professional. The worst part about this unit is not that it is breaking the game or that it's OP: it's that it makes the game boring and not fun at all. CoH2 is an awesome game, I f'''ing love it, but right now the meta is terrible and no fun at all. I tried out the ISG with some buddies a week ago, and I didn't even feel rewarded when I had them, I just felt like a cheeser.
"But Pack Howies" some would say, that's a different story, it's more expensive, it's arrival is later, it has to be micro'ed a lot, It has shorter range, a worse barrage, and way easier to decrew and counter, removing the pin from this unit would put it in a good spot, while only removing the pin from the ISG will make it be game breaking still.
Anyway, the solution is to make the barrage cooldown way longer and more inaccurate, like the pack howie, give it a shorter range and make it more vunerable, then the unit would be fine, so you can't just sit at the flak HQ and bombard most of the map.
Or my personal favorite, make it a direct fire unit with a barrage ability that fires indirectly. That would be really cool, give it a cone, so it's like an AI "AT Gun". This way It would really be an Infantry Support Gun. The cooldown would have to be significant, but with this option you could keep it's stats pretty much as they are, except for the range of course ^^