For work, I use a Windows 7 PC and obviously I hate it. It freezes, lags, and it's, well, WINDOWS! So I have been debating whether to bring my personal computer, my macbook air, in to use it for work. My question is this and this always concerns me with laptops. Is it bad to keep my computer plugged in all day? Does this harm the battery? AND can I keep it in clam shell mode all day for my external monitor? Would this affect the battery life/performance? Would clam shell mode make it over heat?