Cultivars, like this tri color beech, often first show up as mutations in parent plants. They are then propagated out into cultivation because of some desirable characteristic. Reversions do sometimes happen in cultivars of plant - it is reverting to a different form. Probably something more similar to it's parent plant. 

The best thing to do is to prune out the branches that are reverting. 

Things like insufficient sunlight, pruning or soil conditions/fertility may affect flowering. Wisteria do benefit from annual pruning. It is recommended you prune after the plant has bloomed, otherwise you may be removing flower buds. I would also ask if this person applies nitrogen fertilizer and how much, as this may cause more foliar growth versus flowering. 

Managing poison ivy in a pachysandra bed can be challenging. This is because the most effective herbicides for poison ivy, such as triclopyr and glyphosate, can affect pachysandra. This article outlines some of the management options: Poison Ivy in Michigan

One option is to use spot treatment and make sure your application only touches the poison ivy plants. There are some "precision gels" out there with glyphosate as the active ingredient (they are in tubes that kind of look like deodorant) that can help you spot treat only the poison ivy. It may take repeat applications. If you choose to use a herbicide, you must follow all directions on the label. 

One other option is to hand pull using proper personal protective equipment. It is important to cover all exposed skin and wear gear such as gloves, goggles, long sleeve shirt and long pants, and to place the plant material in a bag and then into the trash. You may consider hiring a professional who has the proper PPE to remove the plants (MNLA Business Directory for local landscape management companies). 

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