If we're both understanding "locking" as the same thing, you could consider not locking things.
Generally, if frames are linked beforehand, the text does flow automatically. You do have to link the boxes in the regular pages as opposed to masters. Masters only allow linking within one spread.
Also, i don't know if you've come across this yet, look at Master Text Frame when starting a new doc. Then everything flows through the pages.
I really haven't used Quark (4) much since ID3 came out so I'm losing my familiarity with it.
As I said in my earlier response, the good/bad thing about ID - and most Adobe apps - is that they give you 10,000 ways to do the same thing. That makes it kind of hard to answer questions about the same thing. My guess, in this case, is that we're both missing something about the solution. Maybe somone smarter than I will see this and give a better answer.
Using OSX 10.3.9 on a G4