No. It's just the same as standard glass bedding. The differences that I've learned are that when skim bedding you may want to apply more pressure to the action when you set it because it will find the block and the glass will fill in everywhere else. I scoured the internet for more information on skim bedding a few weeks ago and finally just went ahead and did it.
The only problem I had was I wanted to use the floor plate to help center the action screws better. This shouldn't have been a problem but I put it all to bed and then cinched it down with surgical tubing and then realized that I couldn't put the floor plate in with the surgical tubing in place. So I removed the surgical tubing and put the floor plate in and cinched it all down again. I wound up with a couple of bubbles under the tang. It shoots good but left a welt on my pride. I don't plan on making that mistake again. A better idea might be to use pins that will center on the holes through the block and are turned down to thread into the action. Good luck!
Yes you can use the original screws to line things up but I've never seen anyone use the screws to secure the action for bedding. The problem with using the original screws is that they're just too short to work with. You push your screws or alignment pins through the bottom of the stock and hold them or tape them there so that you can add the bedding and then put the action in the stock. Your action screws will probably be burried in bedding and impossible to use. Get some longer bolts or screws with the right thread. Rem actions use 1/4" -28 and I think Winchesters might be 1/4" -32 (which are hard to find but you can use a tap and make your own threads on a nice long 1/4" bolt that you've sawed the threads from). Then your screws can be placed to stick up several inches above the bedding and are readily accessible when you want to screw them into the action and put the action in the stock. I've always used 1/4" surgical tubing to tie the action down into the stock when bedding. I was taught that this minimizes any chance of stress being placed on the action while the bedding sets. I've also started using Marine Tex epoxy for bedding compound and Johnson's paste wax for a release agent. If you do buy an Acraglass bedding kit, I still would recommend paste wax as a release agent. That release agent that comes with the Acraglass is dreadfull and I've had to use a slide hammer to get my action out several times. Hope I helped.