I am using 1/16" contest balsa on my 4.6 oz MHLG. Its been banged around for a couple of months now and the tail has been no problem at all. It has a conventional tail. I have had good results using an iron-on mylar covering from Model Research Labs. I found that it does add significant stiffness to the finished structure and its extremely easy to use. This is much lighter than a fiberglass finish.

Another thing to consider to improve warp resistance on your 1/16" balsa flying surfaces is to make the last 1/2" or so of the surface cross-grained. By this, I mean that the balsa grain will run in the span direction for most of the surface, but the end of the surface will be cut off and replaced with a 1/2" strip of balsa with the grain running chordwise. Just butt the pieces together and glue. When the covering is applied, the butt joint is plenty strong. Do this to the control surface too.