Dear Vitor,
Regarding the offset in rotor thrust between FAST and GH Bladed, my guess is much of this offset is related to the rotor weight term included in the FAST result, as discussed in the following forum topic: The effect of Tilt Angle.
The first three blade frequencies you are reporting from GH Bladed are very close to FAST results reported in Table 9-1 of the NREL 5-MW specifications report.
That leaves me puzzled as to why GH Bladed is showing less steady-state deflection than FAST.
Best regards,