regarding concrete basement floor and adding wall/supports to reduce sag
I would add a steel plate to the top of the column to spread the load on the 2 X 10 s.  Plate about 1/4 " thick or more , This will also compensate for the crush that has already happened. I have been able to find miscellaneous pieces of steel at a local weld shop at reasonable price. There should be some foundation under the concrete floor to support the steel column ; The floor itself can be very thin, I once found a 1 / 4 " thick spot in a basement floor concrete.  So you can't just put a new column anywhere.