#2
Apples and oranges
The RG, I'll assume you mean, has better pups imo. Same wizard neck I do believe. But all else falls short.
The saber has a ZR bridge, which is far superior to the edge III on the RG.
the INF pups on the saber will fall short of the V7/V8 on the RG. I do like how ibanez V pups sound. I actually have a set for that right guitar...
The saber is also a H/S/H while the RG is H/H, if that matters. I personally prefer a H/H or H/S...
The saber also has wave inlays. The RG I believe has the classic shark tooth. I like both.
I don't let pups be a deciding factor. Easy upgrade. That said, minus the pups, I think the saber is the vastly superior ride.
I don't like the body sculpting on that RG series either though...
I'm a saber guy so...somewhat biased.

They're both made in indo.
#3
Different shape, different bridge, different pickups, different layout, different pretty well everything except for the fact that they both say Ibanez and are in the broad category of SuperStrat.

As mentioned the neck profile is the same.
I'm just a kickin' and a gougin' in the mud and the blood and the beer.