UPDATED:
Okay, I realized Python is not that hard after all. I've implemented this on my server, along with a "minimum days to wait or minimum rep to override" function for answering one's own question (as per stackexchange) and admin exemption for both. I haven't added the ability to turn the feature off yet. I had to change the following files:
askbot/auth.py
askbot/conf/minimum_reputation.py
askbot/conf/vote_rules.py
askbot/models/__init__.py
askbot/skins/default/templates/faq.html
The changes create a new min_rep for selecting own answer and a new
vote/flag setting for min_days to answer one's own question. It now checks whether one has enough rep to select one's own question, and whether a) one has enough rep to immediately answer one's own question or b) the min number of days has passed for new users to answer their own questions. Own questions can be answered and own answers can be selected if the requirements are met.
Also, forgot to mention, I added a check to auth.py so answering your own question shouldn't gain you rep or badges.
I've posted the new code here:
http://www.4shared.com/file/7w_PxlNR/askbot.html
Let me know if I've missed anything.