Interesting! I somehow missed that when it was posted at Trollhalla. (Or my memory is worse than I thought...) An update for Deluxe sounds like a good idea.
I don't necessarily agree with all of that, and some of it - such as IQ saving rolls to cast spells - wouldn't apply in my games since they are almost always 5th edition. One thing that particularly struck me is the description of Detect Magic as being an 'always on' ability for Wizards. I've always played it as something that a Wizard can do at will, but it does require that they make the effort to do it (i.e. they tell the GM that they are using the spell). If a Wizard wanted to have their magic sense always active, I'd probably be giving them some (minor) penalties to perceiving non-magical things, since their attention is divided.
Not a big deal, but how do other people handle this spell?
(Dekh, if you want me to separate this discussion from your thread, let me know.)