Re: Saraad. He has the same capacity to just outright win the game as EPORTS portal, which is huge.
It's nothing like Unstable Portal though, that can do ridiculous things because when it hits a high cost creature you get to slam it 3 turns early. This doesn't modify the cost. Occasionally you'll get a super good offclass card, but that's way less frequent and also is unlikely to win you the game singlehandedly.
If you read it as a 5 mana cantrip that's just delayed a couple turns, it turns out to be roughly an azure drake with +1 health and Super Taunt, which is pretty decent.
Not really, being forced to run out something two turns later is a huge drawback. I don't think many decks want to be making a marginal value play (Azure Drake with one more health!) on turn 7 rather than trying to kill the opponent or playing Dr Boom. And I dunno if it's really "super taunt", if your opponent doesn't deal with it you just get to draw one more card at the cost of using your hero power again, that's not game-winning.
There's 190 spells or so (probably will go up to 210ish with TGT), and there's enough of them that its more than good enough to be equivalent to an average draw. Plus, again, X/186 chance to just outright win the game with any given hero power.
This is bad logic. Having a lot of spells does not increase their average quality - they still range from good to bad. The cards in your deck should all be good, therefore drawing out of it is better than drawing from a random selection of cards that could be good or bad, even if that selection includes a tiny number of good off-class cards that won't even always win you the game.
Besides if getting random spells is really such a valuable effect Nefarion does it much better.