Also, don't forget that no matter what, you are unlikely to be sued. Larry didn't write a waterproof, lawyer certified, do-what-I-want-or-I'll-sue-you restrictive license, like RMS did. Larry wrote a statement of intent. Basically, what Larry said was "I made this piece of software. I'm nice, so I make it freely available. I like you to be nice to". Not a "you have to be as nice as I was".

Also note that when the AL speaks of making modifications available, it nowhere states that those modifications shall be under the AL.

You say that "freely available" is a bit unclear, and you offer an interpretation. Now, the AL is unclear in many respects, but not about its notion of "freely available". It even defines the term:

        "Freely Available" means that no fee is charged for the item
        itself, though there may be fees involved in handling the item.
        It also means that recipients of the item may redistribute it
        under the same conditions they received it.

Abigail