I think the issue here is you need to understand that etching is part of marble. There is no way to protect against it. If you choose marble, it's gonna etch. Over time the etching will become less pronounced (especially on a honed finish, I wouldn't ever recommend polished for counters). It will develop a patina that is actually quite charming and attractive. Don't choose marble if this bothers you! Even if you repair the etches, they will come back!