  In this work we revisit the vortex matter phase diagram in layered
superconductors solving still open questions by means of AC and DC local
magnetic measurements in the paradigmatic Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8}$
compound. We show that measuring with AC magnetic techniques is mandatory in
order to probe the bulk response of vortex matter, particularly at
high-temperatures where surface barriers for vortex entrance dominate. From the
$T_{\rm FOT}$-evolution of the enthalpy and latent-heat at the transition we
find that, contrary to previous reports, the nature of the dominant interlayer
coupling is electromagnetic in the whole temperature range. By studying the
dynamic properties of the phase located at $T \gtrsim T_{\rm FOT}$, we reveal
the spanning in a considerable fraction of the phase diagram of a non-linear
vortex phase suggesting bulk pinning might play a role even in the liquid
vortex phase.
