I want to buy a used Macbook Air from 2011 to use it while traveling. I will use it for YouTube, Netflix, video editing (in 720p) and maybe some light games like Minecraft or Roblox.
Added (1). I can spend an extra $100 for the 2012 model. Is that worth the money?
Well i still have an iphone three so probably
Yes it will do all that you require. It can be updated to the latest version of OS X for free so can run all the latest software…
http://www.apple.com/.../osx/apps/
For your stated usage there would be little difference between the 2011 and 2012 models.