Well - the short answer is no, at least not in the way you are likely looking for.
A better answer would be, it depends on how hacky you're willing to get with things.
Interface buttons (Stealth, Cast, Quickslots for weapons/spells, etc) are tied as sets to their respective class/class combinations. So as a druid, you cannot have an interface button for stealth. You should, however, be able to work around this.
I don't see an opcode that will cause your character to hide in shadows, so unless I'm missing it somewhere, adding innates to take care of it is out, as are items. This basically leaves scripting; you could rig up a script to allow, for instance, yourself to enter, leave or toggle stealth mode by pressing a key.
So now you can control your new abilities - all well and good, and quite useless as well without modifying your hide in shadows, move silently, and backstab attributes.
Backstab is hidden and the only way I know to modify it is through opcodes - you have a few options here, either make an item that for example modifies the backstab multiplier on equip, or you could be brave and try to code up a kit that modifies this on level up (take my advice and use an item to get things off the ground, if you decide to dive off the deep end into kit creation after you know everything works, feel free). The opcode for stat:Backstab is 263.
Hide in Shadows and Move Silently could be modified through an editor, such as ShadowKeeper, or through the same method as backstab - the opcode for Hide in Shadows is 275, and Stealth(Move Silently?) is 59.
So there you have it - unless you run into a hardcoded limitation that I'm not aware of, the above should work. Some of it is fairly complicated though depending on your level of modding skill - If you need something clarified, I'll be happy to do so.
-Bryll