Dear Milad,
The EQUIL option of AeroDyn v14 should match AeroDyn v15 better than DYNIN because dynamic wake is not yet included in AeroDyn v15. I would expect that the steady-state solution would be similar (but not identical) between EQUIL and DYNIN, with larger differences expected under transient dynamic conditions.
The warning regarding the disabling the unsteady airfoil aerodynamics routines at high angles of attack is not really a concern. See my post dated Mar 09, 2017 in the following forum topic for more information: WindpACK 1.5 MW - #2 by Jason.Jonkman.
The warning regarding the Mach number exceeding 0.3 is potentially more serious. Are you expecting the Mach number to be so high?
Best regards,