Rivets are certainly not a sign of cheap leather. They are very useful for reinforcing stress points but shouldn't really be necessary on the mainseam of a holster.
Cheap holsters (not "cheap leather"), as in Hunter brand holsters. Notice the straps are riveted to the back of the holster instead of being integral or sewn. Rivets have their places, but are often used as a manufacturing shortcut. A hobbyist should not need to resort to shortcuts. Hunter Brand = cheap holsters.
Glue...one of the problems with it, is if it is used before dying, the dye will not take uniformly. The best thing that can be said for glue, is that it can be used to hold the leather pieces together for sewing. However, the more experience one has with leather working, the less one needs glue.
Lacing: The purpose of lacing is purely decorative. If one wants a holster to attract attention, be on display, be gaudy as a 40's-'50's cinema cowboy (or as Patten would say: a New Orleans pimp), then by all means use lacing to attract attention to your holster. However, you will not see lacing for any serious application. Unless you are as the Gay Lt. Dangle on "Reno 911"...he would die for a two-gun Buscadero, black floral-carved holsters with contrasting White lacing and matching cowboy boots.