So, these seem the most important bits.
"Invisibility on the Rogue" is (and should remain) the optimal play. Agreed. If you want max stealth, start with the best chassis.
However.
Your group is, as a group, only as stealthy as the least-stealthy member. Invisibility is, at times, handy to throw on the tin can - or, yes, even on the Wizard himself - to keep the Rogue from saving his own neck / letting you all die rather than dieing with you, and going back to the tavern to find a more acceptable party (or, if what killed you didn't care about loot, just retiring after selling your stuff).
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Whether "Knock" should exist is an interesting design decision. Personally, I like abilities which communicate "we're too big for this baby stuff", much like SAO Kirito just letting bandits hit him, or Teleport largely negating travel, or teeth negating the need for food to be pre-mushed, or eyes largely negating the need to feel about blindly. I like games that have clearly delineated mechanical growth, as it provides impetus for the game as a whole to grow. But that's a matter of taste.