Select a class with an active or passive skill desired, such as the fighter's Quick HP Regen, mage's Attack Spell, or priest's Healing. Level up, select the skill, and set it to the active or passive slot. Then, change class, and all set skills will remain until you remove them.
Put all your equipment and money in your house. Save the game, then quit. Delete your file, and start a new file. Check your house, and all your items from the deleted file will be there.