do i have to redownload to get the newest version? and if so do i lose my previous progress?
yes u have to download again to update
and no u do not lose your progress (unless u deleted the game prior to downloading the new version in which case no clue as to rather u keep your data or not)
Saves *are* kept in the game folder (under /game/saves), so if you deleted the game files manually, you indeed would have lost the saves.