As for copper, there isn't a problem. Propane installations here in the northeast have been piped in soft copper with flare fittings for as long as I can remember.
The only issue with something getting into the burner would be a bit of copper or dirt from the initial installation.
As for the regulator, just be sure that it isn't adjusted too high. Excessive pressure could cause the flame to lift too far off the tip of the orifice or burner.
There is normally a slight gap between the burner and the flame, excessive pressure increases the gap, and could result in a flame out, and raw gas venting.