My impact driver is great for taking stuck nuts off bolts. Not quite as good for taking bolts out of threaded holes as it can snap the bolt head off.
For taking screws out of things? It's 50/50 on rounding out a Robertson or Phillips head, depends on the "mesh" between the bit and the screw. If you're stripping out the head by hand, an impact driver is probably just going to do that faster.
All this is assuming that Red Loctite is the problem. I'd suspect that they're just torqued up a bit much and there's a little rust. Give them a good shot of PB Blaster every day for a couple of days and try again.