In order to get the death daisy you must kill one of the people in your tribe. Here's a simple way to do it.
1) Chose the Sim you want to kill
2) collect the materials you need to build the room
3) Build the room somewhere where it won't get in the way.(make sure it is completely closed with only one door)
4) Change into the Sim that you want to kill and put them inside.
5)Quickly remove the door.
6) Wait until they die then remove the walls.
That's all you have to do. But remember to fix the walls if they get damaged by the warthog or rain. I recommend to try and stay in the same home so you will know when the Sim is dead.

1 - found - Deep Jungle
2 - found - Shipwreck Lagoon
3 - found - Pier Beach
4 - found - Dark Cave
5 - found - Skull Rock Jungle
6 - found - East River Plains
7 - found - South River Jungle
8 - found - Volcano Jungle
9 - found - Geyser Plains

I have heard about people having trouble getting their sims to successfully propose. Well, I've finally figured out how it's done. In order to successfully propose, you need to make the wedding lei(it's a necklace), which requires 5 white hibiscus. You also need to make the traditional marriage beanie(it's a hat) which requires 7 white hibiscus. However, you also need to have your social status at 100 in order to get the other sim to say yes. After you have all this finished, (I'm not sure if you have to wear the wedding things or not when you propose. I wore them when I proposed though.) the other sim should say yes. If they happen to say no, get the social status back to 100 and try again. Hope this helps with some of your troubles!