On the subject of large pools forging...
Assuming all one billion nxt contributes to forging, an account (or pool) that has 17million balance will forge a block on average once per hour, i.e fairly regularly. Any business that needs to execute lots of transactions each day (e.g. an online wallet service / exchange / alias registrar service / poker game) could lump all its transactions from the last ~1hour into that one block and get them executed without fee. Or rather, it gets its own fee; but same result.
So, big players with big wallets and big transaction volumes will end up not paying any fees, whereas the small fish will have to pay fees. Is this a likely scenario, and if so is it a problem?