We just bought a home that has several plants. I understand how to trim all but the tops. These bushes are 8-9 feet tall. Should they be cut shorter on the tops?
I would wait to prune and trim the Blueberries until late winter or early spring.
If the bushes have not had pruning for some time, I would do a light pruning the first year.
Here is a link with more information.
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
What are the best blueberry bushes for zone 7 (VA). I know I should have two different ones so they will bear.
Most Northern Highbush fall into the growing zone of 4-7.
I would recommend contacting your County Extension Office for a list of specific Blueberries that will do best in your region.
Here is a link to locate your nearest office.
https://www.gardeningknowhow.com/extension-search/
https://www.gardeningknowhow.com/edible/fruits/blueberries/varieties-of-blueberry.htm
Should my friend in Pennsylvania prune her blueberry bushes earlier (now) because the weather will be in the 50's and 60's for the next 7 days?
The best time to prune Blueberries is late winter or early spring, after threat of severe weather has passed.
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
I have alkaline soil. I have read that blueberries, three years old, and now the Hostas I have just planted prefer acidic soil. I purchased a bag of powdered sulfer. Can I just scatter that around my plants to add acidity?
Sulfer is a decent way to lower soil pH, though it's pretty slow-acting, especially if the plants are already established. Ideally you'd be able to work it into the soil, but since the roots are in the way, you'll want to scatter it just like you said. Applications should be no more than 2 lbs per 100 square feet (about 1 kg/9 square meters), so get an idea of how much area you'll be covering and adjust accordingly.
Sulfur isn't the only way to lower pH. You can read about some other methods here: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/raise-acid-level-soil.htm
And here: https://www.gardeningknowhow.com/edible/fruits/blueberries/lower-soil-ph-blueberries.htm
You may also want to get a soil test so you have some idea of where you pH stands to begin with.
A really big branch of a fully grown blueberry bush broke off while mowing. It has loads of new not yet ready berries and blooms on it and a lot of branches with leaves. Can it be stuck in the ground - will it root that way? Or do you have to do a few cuttings and plant them in a container?
This stem is not likely to be propagated as a cutting.
This link will help you.
http://articles.extension.org/pages/29211/blueberry-propagation
recently our blueberry tree got eaten by something overnight. All our leaves and every blooming blueberry was gone, at this point im not sure what to do, will my blueberry tree still produce? The blueberries haven't been turning blue either?
There are many critters that will dine on a Blueberry Bush.
Perhaps a small fence around the plant to protect it may help.
If enough damage is done it can kill a plant, but if it also can continue to leaf out; like it got a severe pruning!
Here are some articles that will help you.
https://www.gardeningknowhow.com/edible/fruits/blueberries/why-blueberries-wont-ripen.htm
https://www.gardeningknowhow.com/edible/fruits/blueberries/growing-blueberry.htm
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
What is the recommended N P K levels for Blueberries?
Blueberries are sensitive to soluble fertilizers and can cause damage or death to the plants.
We recommend organic methods of fertilizing Blueberries.
The link below will help you.
https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-fertilizer.htm