Adaptability is a big thing for rogues, IMO; so maybe an Anyfeat every ten levels? That would be what?... 12 feats right there. If you went with a 1 + 1/10 (i.e. granting an Anyfeat at 1st, 10th, and 20th) that would account for 18 of those 23 feats, leaving you five to play with; make those...