Yeah, but my son is intresting in animals (he creates simple models in Blockbench too) so it’s natural choice to play with animals. Hitting animals - it’s just a game, I think… There is a mummy too so you can use shield (right mouse button) to pass animals without damaging you (or just jump over them).
About ladders: check this out http://akromonit.pl/js/player.js and look for “onLadder”. All ladders are placed on separate layer called just “ladders” To set if player is on or is not on ladder I check tile on player position on ladders layer. Than I have to turn off gravity. But - I can’t allow player to jump because gravity is off and he would fly away. I allow to jump only on the ladder end (when tile on ladders layer and above player position is empty). Being on ladder I can go up using W key and go down using S key.