I'm pretty sure that the moderators and administrators have enough money to get paid for the next 50 years or something from Donators/VIP donations on the past and for Ads auctions now so there is nothing to worry about for that part .
It would be nice to get Shoutbox but it should be free and only allowed to Senior Member and above to prevent some of the spam.
Wrong in pretty much all aspects.
1) Look around and tell me; are there many VIPs/Donators around here? No. I personally only see one or two in a month of reading and posting. That's that too much of a good income.
2) Sure, auctions get a decent amount of income. But go down the list of BitcoinTalk subsections and tell me; how many moderators do you see? An absolute ton. The income gets distributed between most (if not all) of them and that doesn't leave too much for a single moderator. Income for the next 50 years would have to be in the tens of millions of dollars, maybe more.
3) You're just adding fuel to the fire. Senior Members aren't even that reputable/trustworthy. A couple months of posting and you become one. They would get bought and sold so fast that you wouldn't have time to blink; and what happens after that? Spam. That's a pretty horrible idea.
Honestly, there's no need for this. Just go and bid for an ad slot if you want to get promoted. Done.