Syncing Contacts, Calendars, Reminders etc.is working just fine with a standard @hotmail.com iCloud account.
However, when you try to turn on Notes backup, you get:
"Create a free @icloud.com email address to turn on Notes."
I have two question:
- Would you need to switch the entire backup to the @icloud.com iCloud account in order to backup Notes? Will it affect purchased apps etc. if this is done?
- If it's not needed to switch my entire backup to the @icloud.com iCloud account, how would you go about keeping Contacts, Calendars, Reminders etc. synced with the @hotmail.com iCloud account and Notes with the @icloud.com iCloud account?
I think you are confusing syncing with backing up. iCloud supports iOS Backups and syncing Mail, Contacts, Calendars, Reminders, Safari bookmarks, Notes, Passbook, Photostream, App documents and Data, and it also is required for Find My iPhone.
All of these features are completely optional and can be turned on and off at will. If all that you want to do is sync your notes with iCloud, then you can do that. Backing up to your iCloud account or to iTunes on your computer are other options available.
So to answer your 2nd question: you have 1 of your services pointed to Hotmail for everything you sync there, and another one pointed to iCloud for everything you sync there. iOS handles syncing multiple services in anyway that you require extremely well.
I'd say that anyone with an iOS device will benefit from the iCloud features regardless of what other services you use. I use it for everything except for email, which I use GMail for. I've debated forwarding my @gmail.com email to my @icloud.com email to transition to @icloud.com but I've had my @gmail.com address since beta, its well established, and I don't really want to change it. I do like the icloud.com email interface much more than gmail.com. iCloud.com is clean and has no advertisements.