Guestions about Lua & ArcEmu

Hi!
I am kinda new with Lua, and I have been scripting Lua stuff for my server and I encountered problems, like some of Gossip menu buttons won't work!
I have some guestions:
-When you make if (intid == x) then, can those be at any order (x) or in like 1, 2, 3, 4...?
-When you make item script, does the item category and subcategory and other SQL stuff need to be at certain numbers?
-Can the GossipCreateMenu be at the second/third/any function phase where the other stuff is (not gossipmenu stuff)?
-I know it is not possible to make a game object move (like a ship), but if I make it NPC could I make it (having collisions with players)?

Thanks