1) Air Kenya and Safarilink maybe the most commonly choose air carrier you can choose from WIlson-Keekorok. As long as their website have available ticket and payment procedure doesn't have any errors, I would like to choose to book on my own. Information back and forth between you and hotel take much time than usual, everything under your control is top priority.

2) You could have 1-2nights stay in Nairobi before heading to Masai Mara, I would choose to keep luggage beyond allowance at hotel concierges that I stay or expect to stay, definitely free and save over airport. Anything unusual happen on your luggage, talk to hotel guest services better than airport staff.

3) Park entrance fee $70/pp，they mentioned could put onto room charge with bonvoy point credit back. If you stay long, could try to get annual pass for Masai Mara about $400 per year. Hotel cannot do any help on this, I still work on this since 16 nights could save a lot for me.