I can answer some of your questions. Yes, there is a definite effort to clean up the next to useless stuff in the profiles. There are many volunteers attempting to do this. It is one reason why large GEDCOMS and profiles of people living over 300 years ago included within GEDCOMS are no longer accepted--way too many duplicates. People can still manually add older ancestors, but by doing this manually, they have a better opportunity to check each profile for duplicates as they add new people. There are groups within WikiTree who have the mission of merging the older duplications and cleaning up the ensuing mess. Also, GEDMatches will be incorporated into WikiTree soon. It will run a search for all the names in your GEDCOM.
WikiTree, itself, is a work in progress. Chris and company are constantly tweaking the program and adding improvements. They have a very large to-do list of future plans. They listen and respond to our ideas. Recently a new category was established to work on the actual maintenance of the profiles and general health of the tree. Following is the discussion concerning the creation of the WikiTree Arborist:
The idea of requiring people to put in at least one country of birth sounds like a good one, but it may mean a lot of ancestors wouldn't get entered in the system because people might have names (such as Bible entries), but might not know for sure what country their ancestors came from. It still sounds like a possible solution.
Making it manditory to put a date in would be very helpful. There are probably discussions on WikiTree about this very subject. People could at least estimate a birth or death date. Even requiring one date would be an improvement--and yet it might discourage people with large files.
It sounds like you have some good ideas.