Sorry.
Minecraft textures just try to ressemble their real-life version. There is no bad design neither, since we can read the tooltip and you can distinguish it by the lighter and pinker texture of the gravel. It also helps to set the GUI to a bigger resolution.
Trees? An entity taking its place, so the block is rendered as placed but not thought as placed...?
Signs should be lower if the game guesses that a block is placed right over it.
I agree. It is missing, and would be a huge step forward in Minecraft. It always annoyed me.