Yes, such as third party infringement, applicant’s exercise of the invention and prior art search report.
2 months on average.
The initial registration fee for a patent, which covers the first three years of the patent term, should be paid on the date of registration. After then, the further registration fee would be paid per year until the end of the patent term.
The owner may pay the fees any time within six months of the original payment date with the penalty for late payment equivalent to twice the original fee.