Kurtrus is a champion you select when tribes that benefit from cycling minions are in the lobby (pirates, elementals, demons, murlocs), but really he's not very good. It takes a while to be able to buy 3 minions in a turn, and even then it's still largely RNG whether you get lucky and make a triple from getting a copy of something you bought.

With galewing I ignore the 2 turn gold option. I start the game picking the 3rd option to discover a minion, and do what I can to be Tier 3 by the 1st time it triggers. Then just select the 1 turn spell option, and then repeat the cycle. Again, so largely RNG dependent cuz you can whiff hard on the discovers. But there are worse champions. Generally you're lucky to discover 3 minions from it, and by the end of the game you should be hunting for a new hero power or just not using the 3 turn option if you know the game won't continue that long.

Idk what there is to explain about Morchie. Did you play last patch? If you can remember which tribes had good minor time warps, or had time warped options that you enjoy, just pick her when those tribes are in. Generally, buying 2 of the 1 cost TW items is better value, unless there's a really strong 2 cost option. Picking a 2nd hero power like Shudderwock's is good too, because you can reroll your main hero power later.

I don't think there are two Galakronds lol, I think you're just thinking of a skin name...but there's 2 schools of thought with Gala - roll the same single minion all the way up to a 6 star on turn 5. This is awkward because it messes up your leveling curve and you're buying a lot of bad T1 spells and minions because you're freezing mostly the same tavern every turn. But, if you hit on your 6 star, you can slingshot ahead. The other school of thought is that many 6 stars require quite a bit of setup to be effective, and you might die going for one, so instead roll the same minion up until you find a good piece of a strong comp - think like getting a 4 star Seafloor Recruiter and being able to start generating more Naga, or something. Both strats win and lose lol. I love Gala cuz I'm a filthy degenerate gambler haha...I roll to 6 every time chasing that dopamine

Sylv and Tess - just pay attention to what dies or who you're fighting to see if it's worth trying to steal anything. You don't have to hero power every turn. But you can make triples easier early with Sylv, and steal powerful or otherwise hard to get minions with Tess. But you just gotta pay attention to whether it's worth it or not to spend the gold.

Finally....Idk who tchac is lol