Yes, tool enables you to move Outlook calendar to Office 365 using Office 365 Import tool.
Yes,within a few minutes and steps you can move Outlook email to Office 365 online.
No,you do not require MS Outlook to transfer mailbox to Office 365 or PST to Office 365
You will unable to move mailbox to Office 365, if there is no internet connection.
By just going through the simple steps, you can perform the uploading of mailboxes without any technical expertise.