Add anything you want included in export in the includes Dir of your bric. As soon as the bric is added to a page this directories contents is added to the current pages head attachments.
Regarding jquery, blocs has jquery on export automatically but your custom Brics edit environment currently needs to add its own version with every bric, of course you don’t need to use jquery if you don’t want. I’ll most likely make a global jquery linker as that’s a good idea.