HiRise Condo Bathroom vent fan - is it legal

Hi - I live in a highrise condo and am just above the restaurant downstairs. My entire apartment fills with the smells from the restaurant's cooking every single day. The problem is: 1) they vent into the buildings vent column and 2) the fan on the roof doesn't generate as much CFM as needed to pull their crap straight up. So I am thinking of installing a vent fan in my bathroom and have several questions: a) Is this legal to do? b) Will it create issues for my upstairs neighbor?) c) Can I have a timer attached so it operates during the peak cooking times of the restaurant? d) Where can I get a fan that has a 8" square grille? e) Who can help me with installation? Cheers.