1. That totally depends on what you want to program. Programming a printer driver in PHP makes just as little sense as programming a website in C++.
2a. DVD copying and burning: any burning program. Most likely you already have one.
2b. DVD authoring. That totally depends on what should be on the DVD. If you want to make a second Toy Story or Avatar, you'll need more than some software.
3. No program converts all to all. So that depends on your detailed needs.
4. Don't know.
5. That totally depends on what kind of website you want to make for whom.
6. Nothing wrong with MS Office or Office 365.
7. If you buy MS Office for #6, consider buying a version including MS Outlook.

Kees