Generally, if someone offers massage, is BJ or DATY usually on the menu?

That is an unanswerable question. Reasonably assuming that you don't mean an LMT, or some bodyworks-type place at a mall, if a person is offering massage in the adult or erotic section of a newspaper or online site, then chances are that some kind of sex is implied. However, in the absence of reviews, you might be walking into a rip-off, a massage where you are "invited" to get yourself off, a handjob, or MAYBE something better.

No, it is not automatically assumed that massage includes anything but massage.

And many girls limit that to being "above the waist."

on several factors. Are you going into an AMP? Or seeing an independent? As with everything in this hobby YMMV, it also depends on the comfort level of your provider. If you go to an AMP your more likely (in my neck of the woods) to recieve those things you've mentioned, then from an independent. Of course you should research TER on massage parlor girls/independent massage ladies to see whats offered. If your not VIP status, pay for 1 month so you can get some good research in to make informed decisions and have fun!

Every single girl is different and YMMV applies. Your best bet is to look for reviews on TER or elsewhere.