We have two Venture X cards, they're a good deal if you can meet the minimum spend and use the travel credit. You are correct, the high fee is offset by the travel credit, so as long as you use that, it's a good deal.
Lazy credit card churning is pretty simple: get a card, earn the bonus, cancel, get another card, etc.
I focus less on the 'rewards' - the signup bonuses are really the only thing that matters. It's trivial to get 1-2% back on a variety of cards, so it's hard to go wrong.
Chase has a bunch of good signup bonuses too, you can read the "churning" subreddit for some ideas. A lot of the OG FI bloggers have card recommendations/referrals too, I first found the Venture X card from Root of Good. Just set up autopay so you can't forget to pay off your balance.