It is one of those depends answers. None of the stuff you listed is in the wrong category assuming you either did not have a computer or were replacing a fairly old and out dated one.
Example of something that I have seen people do with Financial aid that I do not agree with. For example I knew one person who spent the money on getting a top of the line MacBook pro. Their major and what they used it for was a complete waste. They did do any heavy lifting type of work and was used for surfing the web and writing papers and then they replaced it 2 years later.
Another person used their aid to buy iPod touch and an iPad.
Now using it for that stuff is one thing but then they turned around and complained about their lack of funds and wish they got more aid.
Now in my financial aid I got left over after books I had around 400ish last semester and I am looking at around 200ish this semester. Differences in amount is this semesters books cost more and I did not get as much off selling my books. The money for me just gets tossed into my general funds which the aid turns out to be enough to slow down the bleed off my personal savings to make it to the end of school.
What have I been using my savings for? Things like gas for my car and food and little odds and end. The major purchases have been put on hold. Hell the first big thing I bought myself in the past 3 years was I bought myself skyrim. Yeah a 60 buck video game was my first real new toy that I bought myself in several years and I took the money off one of my books being sold.
Honestly, there's nothing about a Macbook Air that you need, that a PC couldn't do. Is it right or wrong? Morality is tough to call, but was it a necessity? Definitely not. How do I know this? A mac for college is useful if you need it for film/photography/etc., in which case you'd opt for a computer with a larger hard drive and faster CPU.
That is an it depends argument. Windows vs OSX. Even in photographery I could argue now against OSX easily as you can get a lot more horse power for less in Windows and OSX does not provide anything special in terms of tools. All of it is out there for Windows just fine. The only tool that is not out for both platforms is Final cut and lets faces it Final cut X is a joke and is not professional grade. As such the software in uses is out for both platforms.
If you are going into engineering or programming I would say getting a Mac is not worth it since in Engineering a lot of the software you need to use is Windows only and programming a lot of .net and windows studio stuff is used so you will be in that OS any how. Sorry but the dev software out there for OSX is no were near as good as what is out there for windows.
But over all it is a small group of people either way on which OS is better for them is effected by more than personal preferences.