This is not a forum module specific question but more of a general dnn one.  To my knowledge unless you recompile the provider or core code (not sure which one right now) it cannot be done.  No matter what the default is only good until the user changes their preference, because of personalization.  If you are having issues w/ the editor and users you should look at implementing your own provider which 'dummies' down the items available to them. (ie. less buttons).

No, currently it is handled using the personalization built into dnn and hits the db on the click.  I believe if nothing is found for a user it defaults to rich, this is probably where you want to change it.