You can’t drill in CC, only route with a smaller bit (1/16" would be where I would go with this). If the holes don’t have to be “perfectly” 1/8", you could always upsize them to a radius of 0.063" (0.126" diameter). For a cribbage board I think that would still be about right assuming your pegs are 1/8" (do a test cut on a piece of scrap to verify fit). It just wont do any pockets same size as tool (or smaller obviously). I use Vectric VCarve most of the time which allows peck drilling and use a drill bit instead of an end mill.
Yes, CC is very slow when doing a lot of toolpaths. You can unselect the tool paths when doing all positioning, then activate them just prior to preview/exporting GCode which might help. I mentioned this some time ago here:
That flag pretty much stops my PC when trying to do anything, even loading the file itself. However the GCode came out just fine, just took forever to do the drawing and tool paths. CC is a pretty cool tool and simple to use, pretty limited…but free!
Dan