A:AnswerUnfortunately no. The SP8 does have a replaceable hard drive, but it uses a very rare M.2 2230 form factor, currently anything over 128G is insanely expensive if you can find it at all.
A:AnswerNo. One end of the charger plugs into a standard wall outlet and the other end plugs into a proprietary port located on the bottom right side of the Surface.
A:AnswerIt does come with the Office programs installed, but they are not free . They offer a free trial and after that a monthly subscription. I believe the browser edition is free though.
A:AnswerNo, you do not have to buy the operating system again.
Microsoft provides recovery tools that allow you to restore your system onto a new SSD drive.