I'm planning on using my Air at home fully on an external. Only using it as a 'laptop' when I'm at school. Can this have any effects on it? E.g. Cooling, wearing out the graphics.. I don't know if I should invest in a good bit external display or a Mac Mini to use at home.. Preferably the Air + Monitor.. What do you recommend and can you find any problem with using the Air as a 'desktop' 70% of the time.