Hi Renee,
I heat seal with a lighter. It does take some practice, but I find that it works best (but only when there is no breeze!). I cut my ribbon with the sissors and then quickly run the lighter down the edge of the cut. I do have a woodburning tool and usually use that for cutting and sealing korker ribbon, but usually end up getting burned. I got my tool on ebay.
With covering snap clips, it depends on the size. The small 30mm skinny ones cover easily withe a piece of 10 or 12mm ribbon. Glue on each end and in the middle, run under the prong. Or you can use 6mm and wrap them, but I've never been able to perfect this technique!
Don't know about the buttons, so someone else will have to field that one!
Gena