Ruling all squares are 5' in any direction, and turning RADIUS effects into SQUARES, is ... well, I'll be polite, and just say "I think it's a brokenly bad idea".
Nod, this is what I had my game group do. Counting every other squares just got silly. Thanks to some of the area effect examples in UA we have had blissful simple counting! Man, every other diagonal counting was annoying!
IMC we use templates for spell effects so there is not much counting.
For movement may I suggest going a little old school wargamer and just using a soft tapemeasure. I find that it works nicely and is fast especially over long distances (like for ranged combat)