Manual Testing Question:

Answer #1
Report it in bug tracking tool.

Answer #2
first of all try to reproduce it again, if still able to reproduce and report it in bug tracking tool.
Note: be in sink with release notes, some times developers gives some list of modules which are not developed yet/inprogress, then raise it accordingly.
IMP: Dont get any bug rejected by dev team, it will effect the metrics. have strong points with you and at first sight, they should know what the bug is and has to agree that, that is missed from their side and start working on it.

Answer #3
Have to check for reproducible rate and find out is there any alternate flow/steps to replicate the bug.

Answer #4
When report to lead. After report it in bug tracking tool.

Answer #5
When a bug is found, first action is to recreate it 2, 3 times to make sure that it is functionality fault and not due to environment issue.

Answer #6
need to check same case is that bug really exists or data issue, later we can raise it in bug tracking tool