The one problem i see that could potentially happen with the flags and in your idea is people could ban together and then create a WW1 and 2 scenario. I imagined a scenario were flagging becomes so prevalent that we are all limping around with -5 rep. I like the idea it encourages self betterment and interaction. And let's face it anything can be transformed into a weapon.
I personally think another number would be weird. I like the idea but instead of a number have an avatar that has different upgrades and sizes. It could even have animation moves that can interact with other avatars on the comment section. I think it would be funny to see a little avatar jump off my post and fight @scammymcspambot. Ok so that's a bit too far but just a growing avatar next to my profile picture would be cool. Steemit could have multiple options that could be created and sold on the market for more individuality. I really like the inactive user feature, even if it's standalone, I would like to see something alongside a person's name so I can unfollow them.