What's your question? Ask

You will need to replant them and treat them as though they were newly planted. Increase watering so the plant can work to rebuild its roots. If the root damage is very bad, then you may want to prune the plants back by 1/3 or so, to reduce the plant's needs on the roots.

Some fertilizer at 1/2 strength will also help, but make sure that the plants are thoroughly watered before you fertilize them to avoid further damage to the roots.

The one that spins webs is a spider mite. This article will help with that:
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm

The other sounds like it may be aphids. This article will help with that:
https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm

Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-pruning-how-to-prune-a-butterfly-bush.htm
https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/propagating-butterfly-bush.htm

Make sure that for the winter months they are in a sheltered location, like near a foundation. This will reduce the chances that the cold will kill them.

This article should help: https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/tips-for-transplanting-a-butterfly-bush.htm

Don't kill them. Offer them to people who would like one (and warn them about "invasive.") Google "Freecycle Network," find the one in your area, and then offer your bushes to those who want them. People will do the work themselves, since they're free. And, once you get back to the space you wanted it in the first place, contain it. Stick it in a good size container or surround it with metal siding, so it can't creep away. Then, if you live so far south that it pruduces new ones by seeds, do what you have to do to keep plants contained - treat babies like weeds, and pull them out as you find them.