Make an extra sea lane between New Guinea and Middle America.
Changes the game a lot
Also, give the territories better/more geographically suitable names. The main offenders from the classic Risk board are "Ukraine" (which is actually Eastern Europe and European Russia) and "Afghanistan" (which is nowhere near the actual Afghanistan), not to mention all the territories in the Russian Far East like "Kamchatka" (I can't recall the others off the top of my head)
You're right, except "Afghanistan" actually does include the actual Afghanistan.