What should I do after the graveyard and saving Cassie?
Do what you want, I do recommend trying to Win, and Lose, a few times as every character has a Unique scene if you win or lose.
Which sounds easy until you try it.
I forgot to add how to get there, to get there you should have A Ticket to get to Upper New Ark, to the gallery you will meet a receptionist, get a Ticket go ALL THE WAY AROUND and then spook the Receptionist from behind, now to the Island Painting (Painting with a Lot of people) go left into a room a you can see tight entrance you should be able to Topple a Statue, afterwards tell them you cannot Pay and wait...
When all is Over go to the Painting with a LOT of people to find it Empty, rest upon a free bench and into the Island you go.
Lin-Lin, you need Lin-Lin, first do you Remember a Beggar asking for Food?
A Beggar underneath the Dons home, give him food over and over, till he tells you about Counterfeit Tickets, when he does go to the Slum Market, the 'Junk' Dealer should now Carry counterfeit Tickets, buy a few, then get any Massage type from Lin-Lin, in the massage parlor when she leads you to the Tattoo shop, talk to the Counter and ask for a Fix, you need 500 Bits and any shabby Pass to get a 'Quality Pass'
If Lin-Lin, does not lead you to the Tattoo shop, Give the beggar more food till he Mentions the Fight Club, give the 'Devils Drink' Bartender the Pass code, afterwards go to the backroom, a new room is Open, fight till you get Lin-Lin's attention beat her, sleep, afterwards go back and get a Massage with the Shabby Passes.