Get a high enough relationship with the Sim and make sure they're either both teens or both young adults or older.
Chat with our AI personalities
no, there is no murdering in the Sims
No, Sims can not kill each other only the player (you) can kill Sims.
You can't get married on the psp version but i have sims 2 on the pc. how i get sims to marry, they must be in love. be under the boy sim. click on the girl sim, click on propose, engagement. after the engagement, anything could happed. wait a day or 2 in sim time then have your game under the boy click on propose, marrige. :) hope i helped!
There is a cheat but I don't know it. Basically you have to make your sims fall in love (get their life-time relationship above 60) and then you can 'Propose' 'Move In'. The other sim may say no, if they do, you have to get their life-time relationship up even higher and try again. Or you can go to the neighbourhood and move a sim from the family bin into the same house as another sim.
No, a sim cannot murder another sim on The Sims. However, if both sims are enemies, they can hurt each other. You can also use cheats to kill your sims.