I noticed 3 things in the new 1.18 pre release

I have been testing the snapshots for 1.18 Java Edition for a few weeks. I noticed 3 things I feel I should mention. First of all the graphics are much better and mobs are better all around. That being said, sometimes when mining a block, it does not disappear, and mines a second time, it's a minor, rare glitch but it does happen. Happens with all bricks, only in 1.18 Java pre release. Second, when I create a new world in floating island mode, it is nothing but lava pools and end stone, no matter what I set the biome to. Third, I noticed these odd octagonal stone formations with the latest pre release, just aesthetic, but looks man made? Lastly just as a personal pref, from someone who loves your game, maybe a setting to eliminate blocks spawning in the sky floating? It just looks bad to me, my opinion of course. Thank You.