I don’t have any reason to not follow your concept but it might be because of my misunderstanding from your comment item 2.
“Item 2 : Because of cable floor, the height can reduced again to 3 m.”
I thought you prefer to keep the same clear height of the building by raising up this floor to reduced the height to 3m. that why it become the level of MMC/ control room on the +7.25m.
So, for our better understanding. Please kindly correct the elevation of the floor as you require and return us for reference.
By the way, Please recheck and advise on elevation of ceiling in each room because in my opinion, it also better to confirm usage space from floor to ceiling(if any) in this state before design the size of steel structure member.