Hey Mate - in answer to a couple of your questions

1. The Tokens are released to the company each month - not to the exchanges - it is up to them to use them as they see fit (by selling onto an exchange as needed) and the rest get locked back into a new smart contract

2. I will try to find the number for the number of tokens burnt - but it is very small - however if the Interbank market place is $5Trillion per day (US Fed Reserve number) - and Ripple only get 10% of that that is $500B per day, if the avg transaction was $50M (no idea on that but i would guess smaller) then there are 10,000 transactions a day needed to move that - thats when you start burning some serious coins.

3. You are correct they do not HAVE to use a token on the network - but if they do not then they come back to the same old NOSTRO/VOSTRO accounts that the banks have to keep to guarantee liquidity of the transaction - by instead using a universal (no single bank owns the token) token like XRP they get away from this - high speed pipeline to a market maker, purchase $50M XRP - FIAT straight to market makers account, XRP sent to other end within 4 secs, then sell to a market maker at their end in the currency they want - using Multisig with Ripple being the 2nd party on each transaction - no need to hold escrow amounts.

Craig