The clue for the location of the virus battle machine V4 is "some comp called gascan or something." This is really misleading. The V4 machine is actually in the oxygen tanks in Sky Town. Bottom-right area.
no you can only link megaman games together if it is the same number like megaman battle network 3 blue to megaman battle network 3 white
Go into the room in the Dendome with the net battle machine. Up top is a guy with blonde hair who has the folder for you.
In ACDC area 1, you need delete Metaur Virus to get it. Good luck
currently there isn't any info about Megaman Starforce 4 , but there will be a crossover game with Megaman Starforce and Megaman Battle Network for the DS
you buy it
The final boss of Megaman Battle Network 4 is Duo. It does not matter which version you have. However, after defeating Duo, there are optional bosses.
you get Catcher 'N' from the Red UFO Virus located in the airplane computer that you fought magnetman in (zones 3 4 and 5)
Blue moon or red sun?
In MegaMan Battle Network 3 Blue, to find the bird virus called PanelOut, you can typically encounter it in areas with a lot of panels or tiles on the ground. You may have better luck finding it in areas like DenArea2, YokaArea, or Undernet 4. Use the sneakrun or shadowstyle customizations to increase your chances of encountering this virus.
people with heads
no
yes but you must use a cable