Molasses is beneficial to feed the micro-organisms in the soil, the same way it does in the compost tea.
I think it is a myth that it is insecticidal.
By floral spray, maybe you meant foliar. I have read very mixed reports about use of molasses as foliar spray. Leaves aren't well adapted for taking up nutrients. I think the main point of foliar spraying molasses would be to increase micro-organisms on the leaf surface, which should help prevent fungal infections, but that is sheer speculation. It would leave residue behind.
Re feed mill, perhaps you are talking about this:
Feed Grade Molasses: Commercial grade molasses has sulphur and possibly other preservatives and antibiotics added to reduce fungal growth. Sulphur in most inorganic forms make excellent fungal inhibitors. Antibiotics will inhibit, kill and prevent the growth a wide range, but not all bacteria and fungi. Thus feed grade molasses is not a good choice for a biological stimulant. Care must be taken to read about the ingredients so no ugly little surprises confront you and you don't get the response you want to see.
(this is a good article about the use of molasses generally)
That is why I specified UNSULPHURED blackstrap. If what you are working for is feeding the micro-organisms, sulphur is in the wrong direction. If your Feed Mill carries the unsulphured blackstrap molasses, you can buy it. If it is feed grade, sulphured molasses, it is not what you want.