RTs world view is congruent in this respect. You must have a "universal tea pot in the sky" to account for right being true.
No, you really don't need the teapot. It's convenient, but not necessary.
Way back in college a few of my semesters were spent in ethics classes, and they basically revolved around discussing and arguing "right" from "wrong" but we weren't allowed to use or consider any religious "rules or beliefs". We had to argue using other criteria.
If we felt that murder was "wrong", we had to argue it without any religious aspects. It's still fairly easy to argue that murder is wrong... If you haven't done so already, read some Plato for a rough idea of how it can be done.
In the end we were able to argue reasons that the "big ten" rules were important even without any consideration for whether a teapot was up there or not. Essentially, those rules are just simple rules that enable people to exist in a society. If people break those rules (within the society) it causes internal issues and the society will work to resolve those issues.
The teapot argument only works within your own society. Since there are many societies in the world, and more than one teapot, the one that any given society chooses can't be said to fully define truth. Those other societies may have their own teapots, and while their "truth" is just as valid as yours, it may not agree with yours.
When it comes to life itself, I'm not sure I'd argue that anyone or anything has a "right to live".
A right to defend their life? Yes, absolutely. Even a criminal on death row has that right, IMO.
But a right to be alive or remain alive? No.