Hi pmeqele.
i have used planar mapping as you have suggest. so far it has made my work a lot easier than before. have also started using Selection sonstaraints while doing the mappingso the work load has come down by akmost 50%. tht was really helpful was actually doing them one by one earlier now i have combined most of the parts in the building tht have the same orientation and doing it accordingly. also thjis is great fortilable textures as kanooshka had suggested thanks a ton guys.
As far as the lightning rig is concerned i havent done much with the scne as of now. wanted a bright sunny afternoon giving it a mood off one of those days when one just wants to lie down in the sun and relax Or go to Museum :D. have used MR physical sky and sun in this scene and a directional lights along with two area light just for the photons. was using MR portal light along with area light earlier but did not find it any different from the rig i created now. plus the render time was taking ages. found a few use full things while doing tht process like one being tht while using portal light along with physical sun if i rotated the Area light that had portal connected to it upside dwon it made a great night scene with a few tweaks of course. really wonder why tht happened.
Right now i have not used any AMbient occlusion in this scene but will once i start rendirng the final out out you are right this cud use some nice AO. the plan is to get it textured fst and get a proper light setup doone and then experiment with the MAYA 2009 various render passes tht have been introduced