Would a 7 mb camera be good enough for filming?

Answer 1

For filming? As in taking movies? The answer to that is no, because cameras that have a movie mode record in a much lower resolution than their still picture mode: 480X640 is typical, which is the about the same as (low definition) TV, but the quality is not nearly as good as professional television cameras.
For taking still pictures, 7 mb will give you decent prints up to 8X10 inches and reasonable prints up to 11X17.