IMO, your comments are correct.
Going to the UN has allowed our enemies to organize. Now if we attack without a further UN resolution the UN will give aid and comfort to those who will portray Saddam as the victim and the US as the threat to world peace We would have been far better served by attacking and ending it quickly, just as we would have been better served by quicker and more decisive action against the Taliban. Swift, sure and fearsome victory are the best deterents against further terrorism.