Can't say I have too much problem with either one, but I make lotions and lip balms, so maybe I'm just used to it. I agree they melt at higher temps than most soaping fats. Beeswax melts about 160-170 deg F. Stearic melts about 190-200 deg F.
A double boiler is effective and safe and is my preferred method. I just crank the heat until the water comes to a bare simmer and I get reasonable results. Microwave is not so good, especially with stearic -- it just doesn't want to melt by itself in the microwave, but it does okay if mixed with other fats. A crock pot would take ages. On the stovetop, it is very, very easy to overheat either one (and rather dangerous!), so I can't recommend that.