I'm in zone 5, if that helps.

Most variegated azaleas/rhododendrons are prone to reversion. That is, stronger growing non-variegated branches frequently appear. In time, they tend to overwhelm the variegated parts. If you wish to insure a variegated fuure for this plant, you should prune out the branches with plain green leaves.

The plain green portions probably bloom better because they contain more chlorophyll and naturally do better. Variegated forms can burn in intense sun - although this is less of a problem in Z5 than in warmer climates - so moving this plant may do more harm than good.

Poor bloom in evergreen azaleas of all kinds is nearly always a result of winter cold. Z5 is very difficult for most evergreen azaleas. This past spring has been particularly tough as well because of extreme temperature swings which damaged buds that made it through the winter.

Neem oil is unlikely to do anything against leaf galls - you're doing the best thing by picking them off and disposing of them.

Thank you. It was a cold winter.

The weather the previous summer is what affects the flower bud set for the present years blooming. A gloomy spring or summer this year has no effect on this years bloom.

If you winter was too tough, you should still see dead flower buds, but they should still be there.

If they are rebloomers, the first bloom depends upon last summer's weather and the rebloom depends upon this summer's weather.