Good ideas Kzach. I like the idea of at will defense spells - it is kind of like using mage hand (or whatever it is called in DDN) to slightly/weakly deflect attacks. I also agree that some spells should only be rituals or should have some mechanical advantage when used as rituals. I just dont like to see the opening locks or deciphering runes with a wave of the hand.
Of course, Wish should have a cantrip version.
Amongst spells that deserve to do double duty as normal spell/ritual, I nominate Feeblemind. Either use as a straight out weapon, or use as a ritual during interrogations. "If you don't answer our questions, Mr Evil Wizard, you'll be using nothing but baby talk for the rest of your days once he's finished."
Rituals:
Identify
Knock
Circle of Protection
Raise Dead
Animate Dead
Bless
Mage Armor
Cantrips:
Spectral Hand
That's all I can think of right now.
Also, IIRC, Spectral Hand allows you to deal touch spells at range. Probably too good for a cantrip.
I disagree on the opening locks. My wizards have been opening locks with a wave of a hand for a long time, I don't want that to change, especially considering I've been using up one of my spells slots to do it.