Answers

Here are the answers to the questions given above:

1. With merge, you do the integration in a single step (which can be an advantage or disadvantage), and you need to test only a single commit – the result of the merge. You can easily see where the branch began and where it ended. The first-parent view can serve as a summary of the integrated branches.
2. With rebase, you do the integration step by step (which can be a disadvantage or an advantage). Each of the rebased commits might need testing. The resulting history is much simpler, more linear, and easier to see. Using bisection to find regression bugs should be faster with linear history.
3. You can use the rerere mechanism, which automatically reapplies recorded conflict resolutions.
4. Use the git status command.