For Skype for Business Online organizations, you can use the Remote PowerShell in Office 365 to enable your Skype for Business users to use the Skype for Business client or the Skype for Business (Lync) client user interface. The default setting is for users to use the Skype for Business client user interface.
Yes you do - all of it, but under most circumstances, not until after you graduate college (or leave school for other reasons). Under normal circumstances when you graduate or drop below a certain # of units of attendance, you will be expected to begin paying back your student loan 6 months later. For subsidized student loans, this is when the interest will start accruing as well.
When you graduate with student loans (or leave school without a degree), you are automatically granted a six-month grace period before monthly payments begin. Depending on your graduation date, that means you have a month or two left before you must start paying back.