Header/logo questions?
 

What template do I need to change to remove the main logo?

What image size does the logo have to be?

Is it possible for the logo to be a alternating image?

You can do anything you want :) Logo is in skin1/head.tpl. Use Webmaster Mode to find which templates are which.

You could also simply replace the xlogo.gif in the skin1/images folder with the logo of your choice, but make sure you name it the same. Also Keep in mind that if you use something larger in width size than the original it may move your speed bar location, if you leave it in its default area that is.
:D