At the rubber boot where the shifter enters the trans, I am getting a little bit of trans fluid on the boot. Just a very small, slow leak. Is this common? Easy or hard to fix? Leave it be?

Shift lever seal. If it has a bolt on end where shifter rod bolts to trans, under rubber boot then you can change the seal in car. if no bolt on end under boot then the trans has to come out and go to CSR to be fixed. small leak want kill you as long as you keep the level right.

How do you check the trans fluid level on this car?

if you look at the top of the trans where the speedo gear thing is inserted, you will see in the casting the info on the correct level for the fluid. you can measure this with the speedo gear thing when you pull it out, or with a ruler. Wise man (Steve Fenske) told me to only put 2 qts. in trans, which is lower than the case shows. It allows you to pull the axles without making a mess, and if you fill to where the casting shows you'll have about 2.5 in there.