First of all, the muzzle blast is hellacious, as I said.
Second of all, if you can get less recoil and four times the range of a 30-30 out of a reduced .308 load you have somehow created a whole new science of ballistics and basic Physics.
If you actually shoot them both it will make more sense...
I have several 18" 308 carbines and never really notice the muzzle blast, but if it seems excessive to you, that's likely a difference in individual perceptions...it doesn't bother me, and my 94 seems to kick harder from the bench than my 308s with full power loads, but both are relatively mild.
The 308 benefits muchly from the greatly improved BC of pointy bullets vs roundnose bullets...that's just basic aerodynamics...
But when I need to make shots at distance, in actual use not on paper, and if I need to hit something on the ranch that's wary and way out there, I can shoot any of my bolt action rifles and consistently make shots I wouldn't even try with a 30-30 lever.
They are two completely different platforms...there's really no comparison. Even when loaded with spitzer bullets, a lever 30-30 is still a far ways from being the equal of a similar size 308 carbine.
The 7-08 is always a good choice, but might have to be loaded down. A standard Creedmore is a high performer with mild recoil. A 243 is a real work horse with the right bullet, and low recoil even with full power loads.
Actually, any of the rounds they chamber in the RAR will be fine and still be more capable, even with reduced loads, than the 30-30.
A RAR is a decent working tool for the least money, so if she likes the rifle, pick one and load it down the way she likes it.
