I'd suggest you turn off your pumps for a few hours while the sand settles, so you don't sand-blast your impellers
I changed socks for over 12 hours after I added sand, and I hate to think what I did to my return pump
Skimmer may be spewing due to the LR being out of water for a bit, or the oils from your arms and such
Once the sand settles, turn you skimmer back on and let it overflow for a bit to get rid of any oils you may have left behind ... just a thought