I would suggest going back through the pages listed below...
I recently did a similar search and found many older posts that covered all and every need.
Seems no one is here anymore or willing to assist anymore unless you post some pics and have a detailed list of research.
Many with so much knowledge gave detailed help and posters did not even thank the effort provided.
Time spent to help out takes time...
Trying to assist with verbal descriptions when landscape is so visual....

You may find that the juniper grows back from the roots. I am surprised that beavers ate juniper since they prefer other foods around here. If the roots are gone, beaver weren't the culprits; I'd look for two legged pests.

The lantana I have seen has been fairly low growing and shouldn't be too high. Beavers prefer woody plants, so if you plant herbaceous perennials such as low growing ornamental grasses, which have very tenacious roots, or strong-scented herbs that like a hot slope such as lavender, artemesia, or Russian sage you may have better luck.

Depending on your area, can you add something to discourage the beavers from accessing your plants such as a sturdy wire fence that is low enough to not impede your view but high enough to make it difficult for the beavers to access your bank? Can you put collars of wire around your plants so that if they chew them back some, they can't get at the central growing stem? Wire painted the same color as your rocks will blend in fairly well in many situations. Can you add motion detectors attached to flood lights or wind-activated ornaments such as pinwheels or a kinetic sculpture? Is trapping legal in your area and would you consider that as an option?

Don't let sleevendog discourage you, as I haven't found his/her statement to be the case: "Seems no one is here anymore or willing to assist anymore unless you post some pics and have a detailed list of research." Detailed research isn't needed, but a photo will help. You know your area, but we don't, so the more information we have the better advice you will get. How large the area is and how steep the slope is may influence what is practical, and the term riprap covers many possibilities, depending where you are in the country, so the more information, the better your likelihood of success.

I know nothing of lakes, beavers or snakes. But Lantana and most Salvias are not any taller than Junipers or Berberis and certainly lower than Crape Myrtle. I'm also wondering why snakes would like ivy as shelter but not other spreading shrubs.