I didn't pull 30,000 miles on the transmission out of the air. I believe the professional techs on this site support that frequency based on what they have seen in the actual service, but if they disagree they can surely correct me.

The work around for the temp/level is to measure the level right after a cold start and record it. Drive the car over a specific route of about 20 miles. Check the level and record it. Drain the fluid making sure to collect it all. Measure the volume. Refill the same amount short a pint or so. Check the level after a cold start. Don't correct unless there is some gross error (which there should not be). Drive the car over the previous route and check the level. Adjust and seal the dipstick tube. Sounds like a lot of work, but it really isn't that bad.