RE bug reports: there is also google code to post bug reports to: http://code.google.com/p/web2py/issues/list i know that at times things get backed up, and occasionally a bug gets missed, which is why we have been encouraged to start using the google code bug tracking.
RE modifying field types and removing fields from the database: web2py does its best attempt to keep the database in sync. it does not delete fields from the database, and changing types and certain restrictions it won't be able to update all by itself. as you get into the more complex migrations (ones where web2py doesn't know how to transform the data) you will have to write SQL by hand to do it. for my most complex projects i do all of my migrations manually. if you notice areas where the migration can be generalized i'm sure massimo would consider a patch. good luck! christian