The questions are irrelevant to Buddhism, but not in the sense of comparing it (as a worldview) with Christianity and other religions.

I disagree that Buddhist don't make factual claims. They believe in rebirth don't they? That living creatures are actually born again as other living creatures. They claim the actual existence of a soul and life after death.

Also, I disagree that salvation is not a Buddhist concept. Nirvana can be seen as a kind of 'self salvation'.