Take some comfort in the fact the transmission is a pretty tough device. From what I've been reading all you have done so far is limp home in first gear. I haven't seen anything that would constitute major damage - even if they did put in the wrong modulator, its no different than driving around in first gear. No reputable shop would say its normal to find ATF in a vacuum line, because its not true. Something's wrong with that outfit. Wait and see what happens with the correct modulator. I expect you will find the tranny shifts just like it did before, maybe even better!

Let's hope for the best....