2. https://git-scm.com/docs/git-reflog
It’s very hard to loose data in git.
3. The goal of writing code is to have working software. Conflict messages are like compiler warnings, better have them than getting errors slipping by unnoticed. If A conflict with B, the root cause is often a design conflict, which means that the design of the software is inconsistent.
The conflict only matters as long as it’s not been solved. For each commit, the design of the software need to be consistent, and the succession of commit describe the evolution of the design. A is not lost, B is not lost in the case of a merge and may stay for a long time when rebasing. C which solves the difference between A and B (and may replace B) is also consistent. I don’t care about inconsistency.