@common man for first point, no, hni will be hni only and will be allotted as per amount applied and as per subscriptions, only thing is that share transfer will happen and subscription counted will be equal (in fixed price ipo) only.
Read comment no. 11 from me here : https://www.chittorgarh.com/ipo/ipo_discussions.asp?a=1468&c=630622&ap=0
regarding second point, its mainly depends on subscription and luck , basilic will be subscribed more but ya returns are also more.