dave, take the spent blooms off - the whole bract (sp? not sure if that's even the correct term for the stem) not just the blooms themselves. they will bloom again when they are ready to.
make sure you've got the water level up high enough so that it will leach through the insert and get to the soil.
you'll see more growth with having them in the self-watering pots. they really make a difference!!
av's will regularly lose older leaves. any that are turning yellow can be pinched off - pinch as close to the base as you can. use small scissors or clippers for larger stems...your finger nails will do fine for smaller leaf stems.
i regularly turn my av's so that they don't end up
growing funky. i also move them around - again to promote even growth.
also, some
plants do better at this window and some do better under the grow lights.
i'd suggest switching yours around and see how they do.