Keep in mind as you read these questions, that my AR is a hunting gun.

#1  From looking at the part in the Brownells catalog, it looks like the QD swivel adapter (for the buttstock) has the hole sideways.  I want the hole perpendicular to the gun.  Does the stud part swivel or is it fixed with the hole parallel?

#2  My barrel is a fluted stainless heavy thing.  I think the diameter (at the muzzle) is close to an inch.  I've seen replacement gas blocks sold for my barrel.  How hard is it to switch gas blocks?  IIRC, it has two pins through the bottom.  I currently have a squarish gb with a rail on top.  I'd like to switch it to a more sleek one with no rail.
ETA: Something like this

#3  I currently have a cylindrical FF handguard.  Is there a lighter option that is more sling/bipod friendly?  I don't need a 4 rail hg.  Mainly I'd like something more ergonomic and with a permanent sling stud.  Maybe skinnier too, my round one seems fat, sticking out past the upper on both sides.

#4  I'm using BMAS (YHM) risers right now along with Burris high Z rings.  A new hi rise upper is about $135.  I like the look of the high rise better, but is it worth making the change?  Could I get any money out of my A3 upper?


I am seriously considering making some changes to get my perfect configuration, then having it professionally camoed.  

Thanks!
Jim

If you're gonna recoat anyhow why not have the mount you want milled into the HG?

I actually have a working bipod forearm sling adapter right now.  I'm just looking for suggestions on a handguard that is a little more friendly than the one I have now.

I've done a little searching and reading and it sounds like I could get a replacement gas block with set screws.  That way I don't have to worry about the pins, right?  I don't really like the clamp on one from Brownells, looks cheesy.  I have last years catalog at home and they have a good looking gas block in it, but I can't find it on their webpage.

Jim