I used to think the same of my shooting (still do ... nah, just kidding). Seriously, it's like learning to drive in a Ferrari - you only need to worry about your own limitations, and not those of the vehicle. From what I've seen, your well on your way (considering your water shot from just the other day).
LOL - I DO hope to get over those ways at some stage, but probably not for a few years yet And you'll have up to 8 stops of "dark" at your fingertips in a few days! Think I prefer my DUAL Digic III's to a lonesome Digic IV (rumours of a new 1Ds series camera soon anyway )About your trip, I would love to host you in Boston and show you around. New England area some of the best landscapes in the country, let alone some of the most historic architecture! And for gear, as long as you don't need anything more than 3 stops dark, you can rely on mine... And about the camera, I do not think you will have any problem using the DIGIC IV processor at all