None of my eels uproot plants, i have six spiney eels, of five different types.
My peacock eel is small and active and tbh, couldnt uproot a plant if he tried.
If an eel is forever dashing into the substrate then your tank is too bright and he is acting scared. Whilst spiney eels are substrate burrowers, this is an emergency live saving behaviour, not one a happy eel in a suitable environment should be exhibiting on a daily basis.
I wouldnt be happy putting a delicate eel into a tank with that shark though.... although two of my eels share with an albino red finned shark, hes less aggressive.
Be sure of your eel also.... two types are commonly called peacock eels.
They are, Mastacembelus Siamensis (true peacock eel) which shouldnt get much past 10"
and
Mastacembelus Aral (one stripe spiney eel, also called peacock eel), which will get to around 2ft and is too big for your tank.
Em