Re: V-Tac Sling Attachment Points??
I would suggest using the blue force gear butt stock adapter for the M16 (if you want a non QD) or the tango down M16A2/A4 adapter (if you want to use a QD) for the rear.
JP makes an uncle mikes style QD attachment for the hand guard, and that is what I would do for the front. It would give you the versitilty you need, without getting too complicated.
I run the VTAC without the Fastex buckle on the front because I have a pushbutton QD on the front. Keeps it from rattling around in a vehicle mount etc, and eliminates the plastic from the sling that seems to make noise contacting anything, especially worn gear.
You could always use 550 chord around the front end of the butt stock (and through the JP hand guard slots for that matter). I've seen that working for a lot of folks who work on the two-way ranges. It's a little more redneck, but it is uncomplicated, and noiseless.
Hope that helps a little.