Robert_Charlton - 8:00 pm on Apr 11, 2013 (gmt 0)
rocco1999... welcome to WebmasterWorld. You're wise to want to plan this out in advance.
My initial take on this is that I would do it in steps... not all at once. I'd make the broad domain migration/consolidation changes first, one at a time, to give Google a chance to figure out the new domain relationships at each step... and then deal with the redesign and restructuring.
So, establish the .net to .com 301... then the subdomain... and then the restructuring.
You don't mention anything about the size of the sites, CMS systems, etc, and nature of the urls, though... and the types of url changes that would be involved in the restructuring, which can affect the approach and add levels of complexity. Definitely, do a backlink check to see what particularly important backlinks you might want to pay attention to, if you can't set up global rules to handle all pages.
There's also the issue of dealing with the .net to .com redirects and then subsequently with the changes in the .com structure.... and avoiding chained redirects of inbound links on those pages that are affected.