what u mean "just", if i was u, i would recharge the AC anyway, change all fluids, spark plugs might as well. that way u get a fresh record keeping start.
u never know when the last owner charged the ac with freon/R-134a , u might have a leak. might as well take it to be inspected and recharge it.
as for the window, window switches or fuses blow out, check those as well. not too sure though.
the temperature gauge on BMW is always on the middle, don't be scared of that.