well, what you're doing IS freezing, really.
there is this: http://www.fxfreeze.com/ , but i don't think it's really better than what you're doing.
you could wait to do sidechainging until the very final mix. then you could use a scope compressor. taking individual tracks out of logic(you could do SOME submixing if you want for convienience if you want) and mixing in scope will REALLY improve the quality of your mixes. mutes and volume automation could still easily be handled in logic, likewise auxes, as they can be sent out individual asio sends.
of course, for tracking, it's all too complicated. while tracking, you'll want to continue just having a stereo out, but mixing is another story. the scope mixer's summing is FAR superior to logic's, scope approaches the best of analog in that category. also, since scope's environment is basically latency-free, integrating external effects is not a problem.
i'm sure you know a lot of this, i'm just putting it out there...
your computer should be reliable and, in normal use, crash-free. if it's not, we just need to find out why and clean it up.....