Hi Phil!
Welcome to the forum and that's one great first post!
You've got a very long list there, unfortunately I don't have time for an indepth reply right now but i'm sure some other dob owners will have time to write some more.
What I will say though, is that you have made a good choice in the 10" dob, it's exactly the same as I have. The premium model with the crayford focuser is a good upgrade from the standard rack'n'pinion. I replaced mine with a
moonlite focuser, as the "premium" dob wasn't available when I bought mine.
Are you getting the standard 4 plossls with your dob? Where are you getting it from? Andrews? Bintel? Sirius Optics?
There is a lot of things in your list there that in my opinion are mostly unnecessary, and you won't need straight away, if ever. You'll definitely need to prioritise and the "nice to have's" can just stay on teh wish list until you've had more experience.
Having said that, I don't know what experience you have.. Have you owned a telescope before? Have you looked through any telescopes before? Your experience and prior experiences will help us determine what might be best for you right now.
Forget all that paracorr stuff, it's simply not important right now.
3 collimation tools/devices? You only need 1, plus practise.
A telrad can work with a finderscope, but most people use 1 or the other. You don't need a RACI finder either. The one that comes with the scope is perfectly fine. You'll only need to think about an RACI finder if you feel the straight-through finder is uncomfortable to use.
If you get an ArgoNavis you'll use your finderscope/telrad less and less, but again the ArgoNavis is a luxury and certainly not a necessity straight off the bat. I rate DSC's very highly (you can read my
review here, but it's not something i'd recommend to someone buying a telescope for the first time until they'd had some time to use it and learn how to use it first.
All the books and atlases sound fine, but it also looks like a bit of overkill. Start with a good planisphere and star atlas and some software for your computer (starry nights or CDC). If you want to learn more about astronomy then there are some good beginners guides to start with too.. Also Astronomy2005 is the best overall month to month sky guide that's around.
H-beta and O-III filters - forget them. Especially the H-beta. The h-beta is useful for 1, maybe 2 objects in the whole sky. And it doesn't help that much. The OIII filter is good, but again it's not something i'd recommend to someone new. When you've had your scope for 3-6 months, and have some experience under your belt and you can recognise the difference in what you're looking at, that's when I'd recommend it.
If you get a 2x or 2.5x powermate, you don't need a normal barlow. Powermates are better than a barlow, but they are also a lot more expensive. It's unlikely you'd notice the difference until you had more experience, but if you can afford it, start with the powermate and you'll never need another.
You don't need a star diagonal, they're for SCT's and you simply won't use it with your dob.
Accessory case, for sure. You'll need one of these. Though you don't necessarily have to buy the name brand. You could probably make or buy a cheaper one elsewhere.
Forget the coloured filters for now. I bought a set and have used 1 of them, once.
The polarising filter is good for the moon. It reduces the glare so it doesn't completely ruin your night vision!
Anyway I wrote for longer than I expected. I'm sure guys like Starkler, ausastronomer, mhodson and other dob owners will be able to add to or correct what i've written.
Good luck!