i think most players who know how to use a computer will intuit that since mouse left and right are both used, and the game has a custom cursor, that mouse movement is used. as for the name, it's not required that you have to type in a name at all and you can skip it with an empty name
I'd appreciate it if the controls blurb mentioned that you needed to point the mouse at a block to break it with the pick. When I started the game, I spent FOREVER swinging my pick at the nearest tree and wondering why it wasn't getting cut. I mean, the sprite was hitting, and mobs took damage, but why wasn't the tree affected? Did I need an axe, but how do you craft an axe when you can't break ANYTHING? Watching a few let's plays showed the youtubers breaking trees with no difficulty. So was my game bugged? I deleted the world and created a new one, issue persisted. Did I need to redownload? Did that, same issue. Was I aiming the pick wrong? Maybe jump up and down? Nope!
I'm not quite sure how I managed to figure out you were supposed to point the mouse at what you wanted to break. I think I managed to break a block by accident and went from there. I imagine it would have been obvious for people who'd played Terraria before, but I don't tend to spend for games, so...