Sure... if you're using nylon washers it's easy. Just use a knife (hobby or pocket, whatever) to cut notches in the bottom of the washers to accommodate the surface mount components. If you do a good job you can keep this set of washers (mounting screws, whatever) with the motherboard through several block changes.
probably not a agood idea, superglue bonds two materials together by physically melting the two surfaces and then fusing them together.
melting and motherboard pcb just dont seem to go with each other too nicely.
You could also go to the plumbing repair section, where they have faucet washers, and pick up some. They are fairly stiff and black, but not as soft as rubber. They'll conform around your components without cutting. You can trim them to the OD you prefer if you'de like, by using a razor on a cutting board (if they don't have the small OD ones).
I used soft vinyl washers that did the same thing, but the imprint is permanent on the washer. You can tell them from the hard plastics like delrin by scratching them with your thumbnail.