Yes, the scope will work fine without them. They are there to reduce EMI.
I would have left them alone. To do a good PM, you'll need to check all the electrolytic caps, as long as Rifa caps. Dust the inside, deOx iffy connections, etc. I wouldn't bother until something fails. I have room full of stuff. I only had one incident of Rifa failing and few on electrolytic caps failing. Just because they are Rifa caps, it doesn't mean they will definitely fail.