Anything I could do in 5 minutes or less with 100% certainty and could apply for millions of users?

Someone mentioned earlier we need a sales person's perspective... so I'll throw in my 2 bits.
I agree that the majority here is correctly identifying that Bitshares main core is (and I'm listing in order what I see as priority)...
1) The DEX
2) Core SmartCoins (USD, CNY, EURO, etc.)

Since the DEX is the main backbone of our system, IMO it would be silly to over tax the activity of the exchange and in turn, dry up any incentive for future/present trading.  The only way (again IMO) is to set trading activity fees pegged to a percentage. I can see 0.5% being a great starting charge for trading fee's, but capped at 300 or so BTS, allowing those Large Quantity (ie Big Player) traders ample breathing room to play.
Putting this in a number perspective...
3000 BTS order = 15 BTS fee
20,000 BTS order = 100 BTS fee
60,000+ BTS order = 300 BTS fee
I don't see how you can effectively and fairly asses a "regional" fee or flat fee when it comes to DEX trading.

Now obviously we know that BTS (the underlying share) is the crucial life force, so squeezing that available supply line will help increase BTS value while also "guiding" people to start utilizing SmartCoin's more as the primary currency, while also giving more demand for creating more USD, which is what we want correct?   
So for a BTS Transfer fee, in my mind, should be a flat somewhat higher tiered fee...
1 to <100 BTS = 1 BTS fee
100> -1000 BTS = 5 BTS flat fee
and then 1 BTS per 1000 BTS thereafter and cap it a 500 BTS threshold.

For CORE SmartCoin transfer fee's.. I'd make it a percentage base fee of 0.05% and cap it at $5 USD (or it's equivalent to that specific SmartCoin).
So a $100 USD transfer would cost five cents ($0.05). 
$10,000+ USD would be $5 USD fee
Again, this will help keep Big players in the game to do big money transfers utilizing SmartCoins.

For UIA's transfer fees... again, I'd make it a low percentage like the CORE asset fees I just mentioned.  I almost hate saying this... but I could see it making sense to ONLY use CORE SmartCoin's for the transfer fee's of UIA's. 

So all-in-all keep DEX fees low.  Create higher friction for BTS transfers.  SmartCoin fees low to keep the flow!