It's said here that BA will credit you for TP & Avios for the route booked, unlike AA. I think you'll still need to ask for them - it won't happen automatically.

As for the Brussels business class flight, I think your BA flight would have been much the same in terms of seating. I haven't flown LHR-TLV so could be wrong, but if it is like BA shorthaul in general then there are only slight differences between the BA and Brussels Airlines experience. Both use economy seats, but guarantee that the center seat in each block of 3 is empty in the business class cabin. BA offers a better meal service (opinions differ, but that's the idea); Brussels Airlines simply offer a free meal service.

You may well be entitled to compensation for the delay in arriving at your final destination although it will depend on the original cause. Others here are far more expert than me about this and I'm sure they'll be along soon.