storing data for frequently changing forms, how?

I would consider a start schema for what you suggest. You would have
a table that has 3 fields: form ID, question ID, and answer value.
Then you can add or remove questions all you like. Then you have a
form table for each set of answers that is joined to the answers
table. You can use sub-queries to make the whole thing look more like
a simple row in a table/view. You can also use subqueries to filter
the set of forms as you see fit to do queries on forms for specific
answers to questions.