Snow Leopard upgrade help, migration assistant, etc.

I have a several year old MacBook Pro with Tiger on it. I purchased the Leopard Box Set but never got around to installing it, although I'm using Leopard on my work Mac so I am familiar with it.

I have purchased the Snow Leopard upgrade disk and understand you are "supposed" to upgrade from Leopard, although I know you can upgrade, via a clean install from Tiger. I feel as though since I did buy Leopard I have fulfilled the license requirement (although Apple might disagree, not sure).

My backups currently consist of user folders copied to a USB drive with Carbon Copy Cloner (not enough disk space for a full clone).

My questions are as follows ...

A) Must I really upgrade to Leopard before upgrading to Snow Leopard at this point? The thought of doing two full upgrades to the OS makes me nervous... I'm more inclined to do a fresh re-install of everything with a formatted drive anyways.

B) What does the Migration Assistant need in order to run? I've heard external drives are supported, but will it work from an external drive that only has users' home directories present? Or must it be a "virtual" full Mac "clone" of sorts.

C) If the Migration Assistant will work from users' home directories alone, will it successfully migrate Mail, iPhoto etc. (I have the box set with iLife as well as iWork) over? I've heard that the mail format is different in particular but have been unsuccessful in finding a detailed list of folder changes etc since strictly speaking the Tiger --> SL path is unsupported.

D) What does anyone here with experience actually recommend that I do in order to upgrade to Snow Leopard? Two upgrades seems ... stupid, frankly, considering I do legally own the Leopard disk.

Many thanks.

Ok, so I suck. Reading this thread:

http://www.mac-forums.com/forums/os-x-operating-system/168061-upgrade-snow-leopard.html

... more closely it seems to answer at least part of the question, that the wording of the EULA seems to indicate you must not only be an owner of Leopard, it must actually be installed?

Is that right?

That sucks. So I actually have to go through the Leopard upgrade?

What about the Migration Assistant and the user folders?

Thanks for bearing with me,

When i did the 10.5 to 10.6 upgrade i used the Migration Assistant but did not check the box for Applications, thinking being SL had its own Apps and any 3rd party Apps i would download fresh copies if they were Ok for SL. All my User data came across and i had no issues.

Migration Assistant

I understand you don't need to use the migration asssistant to migrate your apps. My question now I guess would be, will it *recognize* just a user folder in the backup?

So after sleeping on it, I'm thinking the most viable option might be a Leopard upgrade followed by a clean Snow Leopard install. My question I guess then is about restoring data from the migration assistant that's just user folders. And I suppose i'd have to get fresh backups from Leopard for Snow Leopard's Assistant?

This is going to be time consuming it seems....