Hi Imran_m_uk,
Let me answer the questions one by one:
Q1) Does Hosted Exchange support IMAP? I'd like to setup my Mac Mail client.
A1: Yes. IMAP connection is supported.
Q2) I assume for iPhone support its setup as a regular Exchange Account
Yes. Please see Set up email on Apple iPhone, iPad, and iPod Touch
Q3) I quite like the look of new Hotmail / Outlook.com, what does the web interface for email look like? There's a lot of screenshots online but I'm unsure as to what the UI is.
A3: The new interface of Outlook Web App (http://mail.office365.com/) looks like the screenshot below:
Q4) I have another email account, on a different generic provider, can I fetch email from that account and then reply back using the same address it was sent to?
A4: I suggest you add the email account as a Connected Account to Office 365.
Best Regards,
Bruce Zhou