Bear in mind that your ruleset differs rather drastically to the standard ruleset. There's a few problems with this.
1. Alienation of a competitive audience. If there is a competitive scene where you live or nearby that you want to attract, tey're unlikely to come to a tournament that runs with improper ruling.
2. 5 minutes actually ends up longer than 6 minutes. It's much easier to run the clock down and time people out in a 5 minute game than a 6 minute game so you'll potentially see more timeouts. From the sounds of it this is most people's first tourney so that won't be much of a problem but that brings me to the next point.
3. Unrealistic expectations of the competitive scene. If you get new players now, they may think that all of competitive is a single character, only omegas and all the rest. This makes it harder to change in the future.
I understand you're running an extremely simplistic ruleset to try and make everything run on time (may I ask how much time you do have?) but I don't think it's for the better. If your players don't understand how stage striking works, they will just go to Battlefield or Smashville and save time anyway. If your players do understand, they're going to be mad frustrated that every game is on Omega when it's like the least common starter to end up on in the 5 stage list. And I don't really understand the single character throughout a tournament thing at all. I play Fox but I struggle a lot against some characters. Now for most of them I stay Fox but I believe that my Link has an easier time against Luigi than my Fox would so I change to Link. Under this ruleset, I could end up against a Luigi round 2, be unable to change and then be out of the entire tournament - not just put into Losers.
Basically, in an attempt to make the ruleset simple and invite more people, I think the opposite has happened. You may get quite a few people, sure, but I'm skeptical as to whether you can grow a scene off this. From the sounds of it your scene is lacking consistent events so this is a great way to kickstart the scene into getting bigger and better.
I mean it might be that your tournament is just running over like two hours or something in which case gooooood luck because that's impossible but meh. If your time constraints are so severe that you need to do it this way then that's fine I guess, just be aware of the problems that comes with that.