I have two hosting plans with Godaddy, I want to cancel one plan and move the domain hosted there to my other plan. I can't imagine this would be difficult even though I got an email from Godaddy telling me it was impossible! The only thing I'm worried about is what happens to my email addresses when I cancel my plan, will these be cancelled to?
With cPanel, it's incredibly easy to do. With GoDaddy's custom panel, I haven't a clue. It should be under "Add-on Domains" or something similar. It should also be noted that GoDaddy does not allow multiple domains to be hosted under their cheapest plan. According to their site, you can only host multiple domains on their "Deluxe and Unlimited hosting accounts only". If you're using their cheapest plan, it is indeed impossible to do.
If you are allowed to do it on your plan, here's how: http://support.godaddy.com/help/article/4688/managing-your-hosting-account-domains
I have two deluxe plans, one windows and one linux, I want to close the windows one and move that website to the linux one, I already have several domains hosted on the linux plan so its quite simple to move it over. What I'm worried about is will I still be able to receive emails at the addresses associated with the windows plan or will they be closed?
As long as you set the email addresses up on the linux plan, and transfer the domains over to that server, you should start getting emails there. I'm still not sure why GoDaddy won't do it for you. Makes no sense.