1) The game will have a maximum character level of 10 - no spells above 5th level. No Wish spell, and even if there were one, it would be limited because every option has to be specifically programmed into the game.
2) The days of PC games coming in physical boxes have ended. No brick and mortar stores carry physical editions of PC games, and the publishing costs of PC games is no longer profitable enough to justify the expense.
3) No. Larian doesn't do microtransactions.
4) There's probably an invisible border because the game developers have to program everything into the game and thus can't plan for everything to allow full freedom of movement in every direction.
You do not want to lose a limb because your party can't reach level 13 and get access to Regenerate spells. Losing a limb probably isn't simulated at all.