I do like when players discover things for themselves and too much tutorial can be annoying and feel like handholding, but I do think being clearer about some things (like the hourglass icon) is a good idea.
You can mine ore inside obsidian rocks with a higher quality bronze pickaxe (see the crafting section of the encyclopedia for tips to increase quality). When you unlock refining and smithing 2, you can attempt to upgrade the quality of your bronze pick too. This is definitely late-stage for the demo tho.
Riding a swampjaw is not going to be a thing - I thought about it, but decided you could tame them too early to be a water mount and made them too small to support the player. There will be a water mount later game tho!
Strange - as soon as you tame the cattern, the chest should unlock, but maybe there's a bug? I'll look into it.
Yes - the two hats look different and unlock for two different skills, but they are functionally the same. There's also two hard hats (with 14 skills, it's hard to come up with unique hats for each one haha).
I should probably have the sword check if there's a wall in the way - although I have to be careful as otherwise people will get frustrated if they feel like they should hit, but it fails as it clips a wall.
I'm glad you're looking forward to the game, and there will definitely be much more dangerous enemies as you get farther away from the demo area.