If you get a White Brothers 80mm M29 with vbrake mounts, you'll be able to put a front rack on. RST have a 29er 80mm with vbrake mounts too if you want to go cheap.

Dyno hub will give you as bright as you can ride without the cops stopping you for having your lights too bright.

My scmidt was way less than that in Aus. Check cheeky monkey.
Building your own wheel is a skill worth learning, it's not that hard it just takes patience.
140 lux for $500 is a complete joke. Buy a housing and MR11 from cutter for less and get 500+ lux, depending on how many LED's you use.
Your light will be as bright as it can be without cars complaining.

mtbr.com forums have an active section for lighting. If by generator you mean hub dynamo, they are a great option especially for the new generation of LED lights available. Otherwise, checkout holders for torches, you'll probably want to carry a torch anyway.

Bikes are only allowed on roads, not trails. I asked one of the NSW park officials about riding sections, and really you're limited to small runs of the trail. Horses are allowed on more track than bikes, which I find patronizing but that's the way it is.

It's nice to have a system, but the practicalities of weight distribution and need to frequently access some things more than others plays havoc with bag symmetry. FYI last trip, my front panniers had tires, tubes and a few bulky but light things. My rear panniers had clothes and sleeping bag. My top of rack bag had first aid, tools (heavy for high up but convenient), money maps etc. My trailer had tent, tarp, water and a back pack with food, cooking, sleeping mat etc.

I've done up to 2 weeks between resupply. Here are my opinions:
- I stick to easily available foods.
- I use canned tuna in oil and rice as a staple.
- The oil is as important as the tuna, I try to eat 20 - 50gm of fat per day.
- I'll eat 300 - 400gm carbs and 30 - 50gm protein a day. I'm 38 years old and 75kg.
- I'm used to eating like this and could eat camp food ad-infinitum.
- If you have to carry water anyway, fancy freeze dried stuff is a bit pointless.
- I use rice instead of pasta because the same weight packs into a smaller space.
- I have museli with a UHT milk packet for breakfast.
- At dinner I have rice with extra things like peas corn etc with a small can of tuna.
- I change flavours around eg curry, chilli, garlic but mostly stick to the same basics.
- On rest days when theres a store, I'll have high protein days, like steak or eggs.
- I never eat junk food.

This topic is why I prefer trangia type burners to the fancier sorts. Just about every service station and rural corner store in australia will have methylated spirits.