I guess liability insurance might be a big one. I know CamoGames has rented out the Claybank site, first time was supposedly a success so they let them run it again.
Maybe contact him in regards to how he did it and for guidance.
Also I think it would be important to mention the safety standards that you place upon players.
Maybe start with a small game (8-10 people maybe) with senior/respected members of the community for the owners to watch first and judge if they want this kind of activity in their building then have a larger games going on maybe 16 players to let them see what the dynamics of having more people are like in a game. Take small steps basically. Finally then hopefully they let you have invite only/open invite (ie. thread in games section and if name not on list no entry) games.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE