Over lining reel weight class.

[boon]

As discussed, you will only damage the reel with 50lb line if you fish it like it has 50lb line - i.e maybe 20lb of drag. It is not a "50lb" reel, I would be worried about the anti-reverse, gearing and level wind mechanism at the levels of drag I fish a 50lb setup at.

If it helps at all, I fish mine with very thin 20lb braid and have never had an issue with braid digging in. I don't think you would have big issues with line digging in with "only" 7lb of drag, either. I use a mono leader for abrasion resistance, but then I'm never fishing off party boats where I have to worry about lines getting crossed or abrasion on the hull; only the reef at the other end of the line.

Lighter braid casts better, arguably knots better, and has less resistance in the water so you can fish smaller weights. But if you need the abrasion resistance on your mainline, there is no replacement for a bit of extra diameter (other than just fishing mono?)