First off I do not use the East American Coast (I guess vs human opponents it might make sense) at all.
The EC is a huge freebie. AI players should use it. Why? Anything leaving there for another off-map destination, such as CT, Aden, or the Canal Zone, does not use fuel. Therefore there are no range considerations. Even xAKLs can make up a CS convoy from EC to CT and run on auto-pilot. EC to CT is a great route for all the dog & Cat merchants you evac from the DEI in the first months. (xAKs carry fuel just fine, albeit more inefficiently.) Pay the transit cost once to get them from their refugee port of CT to EC, then set them up to build CT and forget them for a year or so. They can't be attacked either. Just check on system damage every month and repair as needed. This can be done at either end.
From Seattle: supplies and fuel to North Pacific
From San Francisco: supplies to Pearl Harbor and Brisbane (or Sydney)
From Los Angeles: fuel to Pearl Harbor and Australia.
All WC to Oz routes take a lot of fuel, and the TFs have to be carefully formed for like endurances. Plus, they eat up escorts. Early, you also have to dogleg them around LBA traps, which eats up more fuel and time. The AI has surprises built in which make this route expensive on occasion. On the backhaul leg they eat up a good portion of the fuel they hauled out just getting home.
Oz will make a LOT of supply if you get it fuel. Fuel delivered to Perth from CT, which is a shorter, fuel-economic leg, will flow to the east coast of Oz by itself and start making supply piles. In the betas you can turn industry on and off in Oz if you like, so later on when fleet fuel is needed more than a third million supply at Sydney, you can turn HI off and save the fuel for the fleet.
I'm not saying don't set up some fuel piles across the wide Pacific, but hauling it at full cost each way to Oz from the WC is sub-optimal when you can get it from the EC to CT for nothing, and the run from the CT wornhole to Perth is relatively safe.
From the Middle East:
1) supplies (few) to India
Again, style, but I don't send suplies to India. Bombay and Calcutta make millions of points if you get India fuel. Dump CS tanker loads into Karachi from Abaddan, and it will flow where it needs to go. Later on, when you start doing Big Things in NE India and Burma, you'll need to haul supplies into those ports to flow inland. But India proper is fully railroaded and supplies go when they should, mostly.
2) small tankers send fuel to India
3) medium tankers send fuel to Colombo
I use Colombo as my main fleet base. Against the AI I've never felt a need to base in Bombay, or for sure not Karachi. Colombo is defensible against the AI if you start early.
4) big tankers transport fuel from Colombo to Perth...
Again, style, but this can be a pretty risky route, far more so that CT to Perth. The AI sometimes does CV raids into the IO. Depends on your script draw, and the timing is highly variable. You also have similar issues as with the WC to Oz routes in that a lot of the fuel you bring has to go back into the returning convoys to get them home. Any logistics movement one can do off-map one should do. It's free, except for normal, minor system damage. And it's 100% free of the risk of attack.