Why do my wisteria buds dry up and die before they open (it has the smaller buds)?
Did you have a late frost in your area? If so, it likely killed the blooms. The leaves are less frost tender than the flowers, so it is not uncommon for a frost to wipe out the blooms and leave the rest of the plant undamaged.
After a Wisteria blooms, do you prune the blooms or let them fall off?
It is fine to leave them. If you would like info on pruning wisteria vines, this article will help: https://www.gardeningknowhow.com/ornamental/vines/wisteria/pruning-wisteria.htm
I live in central Iowa, are there any wisteria that will survive our cold winters?
I would try a Chinese Wisteria, it should work fine for your zone 5a.
We just planted the above vine at a corner of a patio pergola where our hot tub sits. It is attached to our garage, which is attached to our house. It is approx. 28ft wide by 23ft deep (the pergola). I don't want it to invade my house siding/gutters. The plant is approx. 3ft high and bushy. It has about a 1/2-1 inch main stem branch at base with profuse greenery on it. I would like it to form a trunk like base stem till it reaches about 6ft then spread out within reason to fill the top of the pergola. The pergola is 9ft high. I also have a yellow trumpet vine just starting out again since being chewed off to the base by the family dog. It is planted maybe 6ft going up another post base of this pergola. Should I move the trumpet vine elsewhere and should I trim off all the foliage leaves from my wisteria until it gets higher? I don't want a jungle growing on my house in 2-3 yrs. I made that mistake once before by planting Boston ivy at the base of my chimney. It was no fun removing that, along with my siding? Can you advise?
Go ahead and move the yellow trumpet vine so that the pergola does not become over run. This article will help you:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/pruning-wisteria.htm
Wisteria buds all formed and beginning to lengthen but are drying up and falling off before blooming. Is there a problem I can rectify?
It is likely caused by thrips. Some varieties of thrips attack the base of flower buds and cause them to dry up and fall off before they open.
A less likely cause may be a fungus.
Treat the plant with both a pesticide and a fungicide. This article will have more information about thrips:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
My wisteria is two years old and beautiful but when will it bloom?
This article should help: https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-blooming-problems.htm
I want to move my wisteria. When is the best time and should I prune it before moving it?
Wisterias normally do not transplant well. You can try it, (now) but you will need to cut the plant back pretty severely in order to ensure that it survives being transplanted. This article will help avoid shock from the transplanting: https://www.gardeningknowhow.com/plant-problems/environmental/learn-how-to-avoid-and-repair-transplant-shock-in-plants.htm
Just in case, I would recommend that you take cuttings or dig out some of the suckers. This article will help: https://www.gardeningknowhow.com/ornamental/vines/wisteria/propagating-wisteria-cuttings.htm