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.
Unlike other federal Direct Loans, Direct PLUS Loans do not have a grace period, or period after graduation before repayment starts. Generally, you will need to start repaying your Direct PLUS Loan within 60 days of your final loan disbursement. There are circumstances in which you can apply for a deferment, however.