YES

The bracing designed as axial loaded members like truss so by definition it should be pin-ended .... Otherwise it will absorbe and share moment based on stiffness

regarding the book .... you can refer to any design book or even the codes like A I code 

best of luck

yes, you should assign hing to brace, you can refer to Fema 356

thank you all.

usually bracing are designed to sustain axial tension only.

Interesting

Interesting

Depends on actual situation of connections in your frame modelling. If they have fixed supports, no need for applying hinge at the the phases before post-elastic phases and after performing plastic hinges you may model the connections as plastic hinges, but if you have designed the joints with simple connections you may consider normal hinges in safe side.