FCC-ee is a double-ring e+e- collider to be operated in the range of collision energies from Z-pole (91 GeV) to ttbar (up to 365 GeV). The design of FCC-ee aims to achieve a very high luminosity, which only a crab waist collision scheme can provide. Simulations for the FCC-ee revealed new types of beam instability associated with large Piwinski angle and beamstrahlung, that may limit the collider performance. A dedicated parameter optimization allows to solve these problems. We will discuss the features of beam-beam interaction for the FCC-ee and the choice of main parameters for maximum luminosity at different energies.