The front sight is attached VIA roll pin, so I assume it's replaceable.
The longer grip is much better at giving shooters more real estate to hang on to. Just like the original it has Hogue soft rubber grips, but unlike the original it lacks finger grooves. Still it goes a good job of soaking up the recoil, but the gun is still too light to be enjoyable to shoot - though much better than say a S&W 442 for example.
I found after carrying it for three days that I had to use the deep inner pocket of a pea coat to "pocket carry", but that's more like using a shoulder holster. - I think an inside the waistband holster would suit the weapon pretty well.
will the fixed sights handle all bullet weights and velocities (90 - 180 grain/600 - 1200)? - The sights are actually fully adjustable for drop and windage, a curious choice on a carry gun.
what is the velocity increase with that three inch barrel over the standard barrel? - I haven't had the chance to chrono any defensive loads yet, since I was just getting used to the handling and filming some action shots, but the 158gr PPU semi-wadcutters I was using was clocked at 740fps
your opinion on recoil? better than the original gun? Definitely, though the decrease isn't as substantial as it would be going from a 2 to a three inch steel gun, simply because the weight isn't there.
balance: muzzle heavy/light? top heavy? - Decently balanced, though the combination of long barrel and light frame makes it feel like it should have Mattel stamped on the side of it.
are the sights easy to line up (front post fits well in rear notch)? are the sights easy to line up when the gun is raised up to your eye? - The irons are much easier to use then on the original LCR, though I'm contributing that primarily to the increase in sight radius. I want to say the white-painted front sight post is pretty slick.
reliability (ftfs, ejection, cylinder drag, etc.)? -Everything seems smooth and solid with the exception of the cylinder release which sends to rattle a little bit.
trigger pull weight for single and double action. is the trigger gritty? any stacking in double action? - The trigger pull is better than comparably-sized Smiths. I like the grip width as it lets me put the trigger in the crux of my finger for fast double-action shooting.
Thanks for all the great questions Murph!