My first question: Is there a way to keep the DEFAULT Version protected and getting edited directly without changing its the Access from PUBLIC to PROTECTED?
Not that I'm aware of; you are living dangerously if you allow the 35 editors access to sde.default. However, to deploy a safer method you'll need to designate someone to perform the reconciles and posts, and in the mulit-versioned scenario that can be problematic: even though each editor supposedly is editing in distinct areas, there may exist the potential for two editors to edit the same feature. In the multi-versioned scenario there will be a conflict detected and the reconcile/post person needs to determine which to accept. (if you automate the reconcile/post process, you'll just set a rule as to which conflict gets accepted: right or wrong..)
I was that guy and the database only had a dozen or so editors, each with their own version. After struggling with the conflicts issue, I changed the edit-model to one 'Edits' version. That way in the event a second edit was made to a feature, that last edit "stuck" and there was no conflict to deal with. That worked well for my application, but obviously I cannot be sure it would work for you.
My section question: Without using a backup of the Geodatabase, is there a functionality in multiuser geodatabase to quickly restore the geodatabase in case of disaster strikes (Missing Data in Default Version)?
You really need to back up your data and know how to restore it. Again, allowing 35 individuals access to sde.default is a disaster waiting to happen.
That should just about do it....
