Wow, this thread for me is like jumping right in at the deep end of the pool.
Let me explain where I am coming from. I was raised in a Seventh Day Adventist home, though I am glad to say that my family did not have the anti-catholic tendencies that infect so many other adherents of Adventism. Over the course of my teen years, the last ten years of my marriage, the loss of a son and the birth of a daughter I have grown very distant from my Adventist upbringing.
I have through study, deep reflection, careful meditation and what I can only describe as a prayerful approach; come to accept the Buddhist path as my own. Specifically the Sanbo-Kyodan (Harada-Yasutani) school of Zen (Mahayana) Buddhism.
As a practitioner I would like to point out that the Bodhisatva vow is something that is lived, not something that is promised. As Aitken Roshi has said, “you do not take the vow, the vow takes you.”
As for hell, it is a gross generalization to assume that all (or even most) Buddhists believe in a hell or its ideological equivalent. Some sects incorporate such a construct through association with Hindi or other regional belief systems, but such a thing is not inherently Buddhist. Mahayana Buddhism is especially unlikely to incorporate a hell concept as it requires a persistent self, which is not something you will find in many Mahayana schools.
As for Buddhist and Christian interfaith dialog, I recommend Master Thich Nhat Han’s books “Going Home, Jesus and Buddha as Brothers” and “Living Buddha, Living Christ” as a good place to start from the Buddhist perspective.