I want to make a super map. Can anyone help me with these questions

I want to make a super map that will take an entire evening to play through... So.

1.) Is it possible to make maps bigger then the maximum size in the editor? I really need to make a bigger map then what wc3 allows. I remeber I used to be able to make 256x256 maps with some file I downloaded, but I no longer can... How do I make maps that big and can I make them even bigger?

2.) Can I use multiple tilesets for a single map in anyway? And exceed the pitifully small tile limit? It says I have 12 points and each tile takes 2 "1" rarely, that leaves me with only 6 tiles to pick from and since my map is huge I need more to pick from.

3.) Can I have joining maps that players can travel between, back and forth, like enter a cave thats a seperate map, exit a cave, during a big multiplayer sesson? Blizzard said the wc3 would feature cave type maps seperate from main maps that you go into...

well for question 3, that comes with the frozen throne editor.
for question 2, get Zepirs editor.
ditto for question 1.

Hmm, get UMSWE as well.
Hmm... Be sure to edit in all your tiles BEFORE you actually start editing. (If you need help using zepirs, just ask).

Regards
Dead-Inside

(You should include some mini-games in this whole BIG RPG style open(?) Adventure)

The Xtra-Editor is good for making HUGE maps...You can make 4hundred something by 4 hundred something maps( dont know the actual number). But if you do choose to do that, you have to make the whole map in that program. Some things are harder to pick up..