Can a bank's lending officers offer business services at a discount that they buy them at? For example, can a bank loan officer give discounted property/business/personal insurance at the bank's wholesale price as a 'value add' to doing business with the bank? The cost to the borrower would be much lower than they could buy it.

That will be a matter of state law and whether the loan officers are licensed, or are required to be licensed by your state to sell such insurance.

In IN premiums are regulated by the DOI, and each person who solicits/offers/sells insurance must be licensed for that specific insurance product.