Leaderboard

IMHO, No. (See section 16.1.1 of ACI 318-08) You may refer to chapter 16 of ACI 318, and ACI 550 for detailed requirements regarding design of precast concrete members. Regards.

1200x600mm should be treated as column; It has a noticable weak axis response (espically as other members of LFRS are about same size in one axis). I don't know about your framing and column count, but % of baseshear resisted by rectangular columns would be greater in one axis and almost equal in other. If you want to get more classy, compare % of base shear distribution ratio between your rectangular and circular columns to get a feel but with the information provided at hand, best bet would be to model it as a frame element. This answers your part 1 too. Thanks.