Structural stuff like this ...without knowing ALL the particulars is only for the experts. Unless you want a new house.
I really do mean it when I say that these issues are best for someone who is there looking at the whole story. I would love to be able to help everyone with their projects and give them the answers. But as Square Eye basically says ,It is the liability and the safety of others we should be concerned about, and to direct you to what professional you will need to help you get the right answer....not an educated guess.