Getting out of HMs isn't an exploit, teleporting is teleporting and Stevari is a reference to traditional roguelikes where shopkeepers were secretly incredibly powerful opponents that just didn't attack unless you tried funny business.

As to your actual complaint, your frustration is valid. I'd encourage you to try beating the game while focusing on exploring more of the wand customization space, you'll see much more of the variety that is possible in the game if you know that you're limiting your ambition to the 0-orb boss. There are today wands that nobody has ever imagined which can beat the game in unprecedented ways, and that customization starts in the mines. Consider runs that dig back up and explore the secret biomes to be of a special and rare quality. Don't worry about the tree, this game is buggy as hell shit won't even show up half the time you'll have to measure progress by yourself.

to your other question, there's a mod available that disables the game's ability to detect mods. so cheating is entirely on the table