no benefits
Not necessarily. They can help unlock inner creativity. If you having trouble with a song, you tulpa can help dive deeper into your brain, and maybe find some riff you never thought up before. Or perhaps on a test your tulpa could help. Plus your tulpa can be a "living" thing of whatever you want, so you could essentially have a video game character or whatever in real life.
i seriously just completely, and utterly hate the idea of tulpas.
as said before it worries me, to death.
Why would your tulpa want to kill you? It knows that if you're dead then it will be too. It cant drive you to kill yourself, unless you are that unbelievably handicapped.