Make raids accessible regardless of lockouts. Instead lock the player from obtaining any loot. This would have the same effect of a raid lockout but allow the game content to be played more than once per week. It would also prevent players from getting partial lockouts.
Infinitely carry lowbie alts? Not happening, it has too many downsides. I'd love to run through ICC with my OP dps chars a few times a week when I have time, I'd do RS more often cause I find it fun, but that would mean that you can get a few friends to carry your naked lvl80 char anytime cause it doesn't hurt their main guild run or anything.