Hello,
I agree with most of what's been posted so far: stick with jpegs for the first few weeks/months, until you're familiarized with the camera.
I'd ditch the split ND: learn to do the equivalent in PS. Polarizer are always useful if you're used to using them.
A comment on Capture NX: YoungOne is the first person I've ever heard (read) saying that NX is "fun". I'm sure it is for him, but for 100% of the others I've talked with, and judging from personal experience, it's really really bad. The user interface is alien compared to anything else on a PC or Mac. (Read here for a longer discussion:
Old debate updated: Capture NX for D300)
Have fun with your D70; it's the camera I've been using for the past 2 years and I love it. First tip: it tends to underexpose a bit, so keep an eye out for that.
Lao