Well, I guess I will be the fist to reply to this post too! lol
Anywho, there's nothing to worry about this time either.
Gerbils are just very curious, so they like to dig and scratch alot.
And for the chewing promblem, there's nothing wrong...gerbils just chew on things to keep their teeth chewed down.(to keep them from getting to long)
I hope this helps too!