I've got several calendars setup on Outlook.com. I am using Outlook 2013 on the desktop. I've found that the access to my task lists via outlook.com is extremely rudimentary, almost useless. I run Android based tablets and phone. There is not Outlook app for my phone - the only solution is the web-based version of Outlook which requires an Exchange Server. I host my email on my own server (not using Exchange) and access it via IMAP. There's also some other collaboration features in Outlook I can't use since I'm using outlook.com (ActiveSync) and IMAP accounts. My outlook.com address is the same as my own domain's e-mail address - I just use it for Calendar and Contacts obviously since I don't have an organizational account on Outlook.com and have pointed my domain's mail server address to it.
Could I not just sign-up for a $4/month hosted Exchange account? I know I can do this with Microsoft, but do I need to setup an organization account with one of the domains I own to do it or can I get assigned an email address to use (I wouldn't use the email portion, just calendar and tasks.) I guess the other way would be to buy an Exchange account from a third party like mail2web.com.
If I start using the web-based Outlook, can I still view and modify my calendars on my outlook.com account from within the full features outlook web app? (I would think so.)
--edit--
At least I found the answer to the domain issue.
"Office 365 Small Business creates a domain for you when you sign up with the services (the domain name includes .onmicrosoft.com)"