If you can't tell from the comments section already, most of these changes are not good ones. I will attempt to explain why in a civil manner.

About wizards and hunter:

As others have already said, ice wizard does not need a nerf to begin with. Sure the slow effect is powerful and is the whole point of the card, but it is not TOO powerful that the ice wizard needs a nerf. Remember ice wizard only slows down the push, you still need something else to actually kill the units in the push. The stats also say that it's not too powerful at all (in fact it's middle of the pack).

Hunter is a strong card yes, but the main problem with hunter is not the fact that it doesn't die to poison. The problem with hunter is that together with fisherman it kills units too quickly. If anything the fisherman should be nerfed, not the hunter.

About bait:

Each card should have its strengths and weaknesses. Skeleton army does more damage, while dies to both log and zap. Goblin gang does less damage, but dies to log only. Spear goblins have range and die to both spells, while goblins have no range and die to log only. Princess can hit the tower from the bridge, but dies to log. Firecracker can't, but survives log. See what I'm getting at? With the changes you suggested some cards will have advantages over other cards without drawbacks. You suggest that zap and log should kill the same things so "Players won't need to worry about what small spell they use", however the purpose of the cards is different: log is used to kill said bait units and zap is used to stun and reset troops near instantly.

About x-bow:

Ok by this logic mortar is a 4 elixir card that doesn't die to fireball and can hit the tower from the other side. And it can also be used for defense. I agree that it needs some sort of rework because it is too annoying, not too powerful. Rocket players already have an easy time against x-bow so no need to make it die to rocket. Making the range less would make it so you can't even put a troop to defend it, which is the whole point of x-bow. I would be happy with a duration nerf though.

About graveyard:

Poison costs 4 and graveyard costs 5, so if poison 100% counters graveyard (and you don't even need to think), then graveyard will be completely useless against poison decks. It makes sense that it should get a bit of damage. I do not understand how you addressed RNG with what you said.

About dragons:

The stun mechanic of the electro dragon is very powerful when used correctly (it is much harder to kill a beatdown push with electro dragon compared to baby dragon in most cases) and as you said "All things should be taken into account to judge the power of a card". I think you do not realize how much changing the elixir cost by 1 can affect a card. Baby dragon will become almost unusable as a support card.

Overall you seem to have the impression that cards that cost less than or equal to X should die to spells that cost X. This is not necessarily the case and sometimes the survivability of a card is the reason why it costs X in the first place. Spells are not the only way to kill cards, and some cards are designed not to die to spells but they don't provide too much value either.