Using Messages as an all in one communication tool, chat, voice and video, requires logging in with one of those other accounts.
I prefer to think of Messages as an application that brings all of your communication tools together.
It doesn't matter which acccount. They all do the same thing, apart from Apple, which is only for chat.
I'm not sure I only use my Apple ID and AIM. I have a Google account which I will probably add today. I know AIM and Google allow voice, video, and text. Apples iMessage only allows text.
- With say, a Google account, I could only talk to other Google Talk account users, so if I want to communicate regularly with a certain person, we should both get a Google Talk account.
- Only purpose of using Apple ID is so that you can communicate with other people connected already using an Apple ID, like Iphone users, for instance.
Yes to both of these.
Essentially, if I want the best functionality with Messages, it's better to use anything but Apple ID if the person you want to talk, chat, or video with has the corresponding service. Messages acts merely as an interface to these other services.
Yes and no, you can be logged in to all accounts at once. As I said earlier I currently am logged in to my Apple ID for iMessage and my AIM. Later I will add my Google and be logged in to that as well as my 2 other accounts. So, log in to every chat account you have that is available in Messages.