Really, there's no way to balance it. Make it too easy and people become gods in half an hour. Make it middle ground, it takes hours to get decent at one thing when there are 30 + things to get good at. Make it too hard... well, you get everyone entering "giveselfskillxp 9999" because they have to spend half a dozen hours getting good at mining, then suck at everything else so they have to spend half a dozen hours upgrading blocks... then shooting a rifle... then shooting a bow... then standing on a catcus because you'd have to otherwise find a zombie to hit you for half a dozen hours chugging first aid kits standing naked in the snow eating 100,000 bowls of stew to gain HP.