I am confused...
"1.1 mathematical objects, if they exist, are non-physical"
"Therefore, mathematical object are not non-physical"
Physicality is not equivalent to non-existence.
So then it is possible to not be physical, and be affected by the physical, for example love.
It is my "abstract" mind that creates an abstract number. So then assuming consciousness (not necessary mine) can exist with out the physical then so to can numbers.