not everything has to be a perfect recreation to be really fun to play. I believe the spell system in this style of game could be very adequate in replicating the effects of channeling, if not the actions themselves.
And balance is no problem. Like... you get yourself one of the broken race/class combinations in the bg games, and you can straight up solo every boss in the game. So, I really don't see the issue here either.
So in summary, I couldn't disagree more. Unless your big thing is wanting to "do" channeling, but... I mean, items can even work like ter'angreal. It seems perfect.
Oh, oh! There's things that can modify your caster level, too, so you could use those to mimic the differences in channeling ability.
Seriously, I think this would be great.