MobileMe to iCloud- many users, many devices

Question

Help!
We're a family of four that has been working nicely with two Apple IDs for iTunes purchases, and a shared MobileMe account for sharing our contact list and multiple calendars.  We're now trying to figure out how to transition our configuration into the iCloud environment.
Current setup -
Me - Mac user (10.6.8), iPhone 4 now running iOS5.  My own Apple ID for iTunes purchases.  I'll likely go to 10.7.2, for iCloud purposes.
Wife - PC user (WIN7), iPhone 4 now running iOS5.  Likely will be getting an iPad2 soon.  She has her own Apple ID for iTunes purchases
Older son - iPhone 3Gs, iPad2.  Both will be updated to iOS 5 in the near future.  He uses my wife's Apple account for iTunes purchases.
Younger son - 1st generation iPod touch.  Not sure if this can support iOS 5 or not (if so, we'll upgrade).   He uses my wife's Apple account for iTunes purchases.
We ALL use a single MobileMe account, to share contacts and multiple calendars.  We love this configuration.  Calendar updates can be done at work via mobileme.com, or any of our iOS devices.  Contacts list is fairly static, but the beauty again is that a change in one place is a change everywhere.  My iCal and Address Book apps on my Mac get their data from MobileMe.  My wife has configured her Outlook similarly.  The other beauty of us all using the same MobileMe account is that all five devices show up under the "find my iPhone" app.
Now, the writing is on the wall for MobileMe, with it officially ending next June.  We're trying to determine the cleanest / easiest / simplest solution via iCloud, since that is the new paradigm.  It appears to involve creating new iCloud accounts for each user.  My kids don't have email addresses yet, so if we make accounts for them we'll have to use our email address.  Can multiple iCloud accounts point to the same email address?  Can iClould accounts be modified later, to adjust for different email addresses (if that changes)?
I see that in iCloud, calendars can be shared with other persons but it appears to be based on email addresses, not iCloud accounts.  I don't know how the sharing is (ease of use) compared to the current model of us all using one MobileMe account.
What would the "find my iPhone" configuration look like, if we all potentially use different iCloud accounts?
Also, as my wife starts to set up iCloud, should she use the @me address (the one we share in MobileMe), or her @isp.net account (the one she uses for iTunes purchases).
Can Cupertino or anyone out there in the Apple base help us figure this out?

Answer 1

iCloud just isn't the same 'flat' offering as in the old MobileMe.  Once the kids get their own PC or MAC, they are going to want to sync their iOS device(s) with their own PC/MAC (not Dad's).  Now is the time to setup the household for the coming few years...
Setup each family member with their own iClound address.  That address will be their own to use across whatever laptops/PC's/iPhones/iPod touches/iPads they now have or will in the future;
You can, if you want, continue to share the same iTunes store account as this doesn't have to be the same as YOUR iCloud account. In other words, you can use different iTunes store and iCloud accounts throughtout the family;
Calendar sharing is easy and won't require you to be on the same iClound account;
The Find My iPhone function can still work across the family's different iCloud accounts by using the new "Find my Friends" app.  It's a good enough work-around that offers similar functionallity to any authorized device regardless of iCloud account;
I hope this covered all your concerns.