In chat, we realized that using a common thread for posing questions to moderator nominees as Math.SE did does not scale well. The general consensus is that it turns into a circus, and after consideration, I agree.
At the same time, I feel that it's important to be able to distinguish the good candidates from the bad ones. A user with 10k rep might not understand the site as well as a user with 1k rep who spends his/her time constantly on Meta, such as myself. Users might not be familiar with specific nominees for various reasons-e.g. they may spend their time in different tags. These users I'm referring to are not the inactive users we don't want; rather, they represent minority sections of our community. However, by asking specific questions as to how they intend to moderate, we can identify those users who might not be suited for moderation, despite their expert knowledge of the subject.
In addition, the current nomination statements are not enough. They tend to be very abstract- I will close off-topic questions, I will do what the community wants. These tend to be either "duh" promises or promises which cannot be proved or not proved to have been fulfilled. It is the borderline questions that we need to know what our nominees think about - we've defined our existing policies for SO here at MSO, and I'm sure the M.SF and M.SU communities have done similarly. However, can we trust our nominees to be familiar with these policies and enforce them even if they disagree with them?
How can we resolve this issue? Allow users (250+ rep?) to each post 1 or 2 questions that are displayed to nominees. (Perhaps make questions go through a vetting process to eliminate duplicates?) Nominees shouldn't be required to answer these questions, but if they don't, it may obviously reflect poorly on their willingness to work with the community. Answers should be publicly displayed to all, of course. This should naturally be built into the election software, since that's the whole purpose of this request.