Merging everything into iCloud, but keeping "send from" addresses intact

So I have a dillema. I'm going to try to try to explain it the best way I can, but just beware it'll get a little hairy.

For a while now I've had three distinct e-mail addresses: My school account (powered by gmail), iCloud (for personal correspondance), and a separate gmail account for everything else. I hate this setup because I have to apply individual rules for every account, resulting in redundant folders and massive headaches.

I made the mistake of opening an Outlook.com account last night and forwarding and importing everything from my two gmail accounts into it. I don't know why, believe me I don't. I should've known better than to expect anything from Microsoft to "just work." I primarily went with Outlook.com thinking that I could finally get everything into one email address, using one protocol (Exchange or MAPI), and would just turn forwarding on for all the other accounts. Well, typical of Microsoft, there were caveats. Exchange/MAPI is only supported on Windows and mobile, and worse yet, there is no IMAP support at all, only POP3. So there went that.

I'm growing tired of gmail and it's "labels" and "filters," and can't for the life of me figure out why they do it like that. And I'm having problems with copies of multiple emails showing up in different "labels," and would really like to let gmail go, but it's the only one that supports IMAP and Exchange ActiveSync (for push email on my iPhone and iPad).

I would love, love, love, love love, to just forward everything to iCloud and have one inbox, one set of folders, have push email, etc., but I have to have the ability to choose which account (school, regular gmail, or iCloud) I send from.

If iCloud can't do it, who can?

BKE