hey i made one of those little splitters and its ugly but it works and thats what matters. and yes you can bevel any size lace. with rawhide you absolutely have to bevel, i practiced on the roo first so it would be easier on the rawhide now that ive started playing with it.
i used to cut all my roo with a lace maker all the same size cuz all i ever did with it was leashes. now i am cutting it differently. check out this video http://www.youtube.com/user/bernie46#p/a/u/0/aDSxaaUyXzY
it shows the right way to cut a roo and from there you can cut the size laces you need. also take a look at bernies other videos as there is really good information there from a top aussie braider. when i cut up my goat rawhides i did it like bernie shows and it is working out really well.