ICloud – How to leave Gmail for Mail

I've decided I want to take the plunge and leave Gmail for Mail, using my iCloud account. Why? I've lost trust in Google (incl. their search bias, how they handle my privacy, and how they treat the end-user as a commodity to sell rather than a customer to serve). I know there are others like me (I just found today: www.leavegooglebehind.com)

I'm looking for answers on how to swap over completely from Gmail to Mail while retaining the functionality I'm accustomed to. I've done a bit of researching and can't seem to nail the answers to my questions. Your answers on any of the items below would be much appreciated. And if you think there's a better way I should be asking the question, please let me know.

Here's what I'm looking for especially:

1. I use Gmail's labels a lot. How can I get the same
   effect in Mail? Smart folders? (I do wish smart folders synced to
   iCloud.) Note: I am not asking about replicating + maintaining Gmail labels in Mail — I don't need to replicate + maintain: I'm leaving Gmail. I just need a system with a similar functionality. Something I could use on both my Mac and my iPad would be ideal.
2. I have a lot of Gmail labels. What's a good way to export
   from Gmail without getting oodles of duplicates? Forwarding folder
   by folder would be time consuming + lossy, and stripping the labels
   would be counterproductive. Are those my only real options? Note: Yes, I know this question does get attention, but a lot of the attention is quite old. Both Gmail and OSX have changed a lot over the last few years. I'd love a good recent resource, based on Lion + Mt Lion.
3. I use a lot
   of Gmail filters. Mail rules seem even better, but is there any way
   to automate transferring my filters to Mail?
4. I use Gmail 'send mail
   as' with a collection of non-gmail addresses (from my domains). Is
   there any way to use my iCloud account to send from a non-iCloud
   address? Or, is my only option to sign up with a different webmail
   service in order to send from my alternate addresses in Mail?
5. Like many people, I
   have my own set of pre-defined Gmail keyboard shortcuts. Do I just
   need to tough it out and learn the Mail shortcuts, or is there a
   good, free/inexpensive app for adding shortcuts to Mail? And no, I
   don't mean through SysPrefs (I know how to do that 😉 ). I mean Gmail
   style single-letter shortcuts, like 'r' for reply.
6. Tips for
   converting Gmail Contacts to Address Book. Note: This area also gets some attention, but again the attention I keep hitting is old.

If you've made the switch, I'd be especially interested to hear your experience! I'd really like to get Mail up and running sooner and rid myself of Google.