Thanks all for the replies so far - just to clarify from a few of the questions:

The original ticket was:

TLV-LHR-JFK-LAS-LAX-JFK-BOS-LHR-TLV

It was changed to

TLV-LHR-JFK-LAS-LAX-LAS-LAX-ORD-BOS-LHR-TLV

The stopover in BOS was due to be almost 2 days (Sunday from early morning and then the late BOS-LHR on Monday). Was due to see friends on Sunday and then meetings on Monday. Had no problem missing the day with friends obviously.

C-W-S - it would have taken them 3 days to get me to BOS missing my meetings in London.
Not sure what I'm expecting here to be honest - maybe a discount on the new ticket or something like that. I don't think anyone's going to fly me there on their "dime" - though that would be nice

The cosmetics were Boots's best, so not worried there.

Didn't think of my travel insurance to be honest - will contact them. ^

Finally, I still think it's BA's responsibility for the BA legs original routing credit and not AA.