Public woohoo happens in the community lots. You need to find a changing room and have your sim try on something from a clothes stall. Once they are inside the booth click on the sim you wish to woohoo with and have them woohoo.
To be saved from death is risky but can be done. First of all the sim who is dying needs to be saved from someone with a good relationship with them. When the grim reaper is reading the last rights to the dying sim have the one with the good relationship to dying sim plead with the grim reaper. He will then put a glowing ball of light in either his left or right hand and depending on if that sims chooses the hand containing the ball or not will your sim be saved. I recommend saving your game right before the reaper turns up if you get chance that way you can try again if need be. I have to say that although everyone says it is risky and not 100% successful I have done it many times and my sim is always saved if the realtionship between them and the saver are lifetime above 80.