Do Sales Discounts And Allowances Affect Net Profit?

Sales discounts and allowances offset Sales Revenues and thus reduces net profit.
Sales discounts are given for early payment of invoices, and sales allowances are given for damaged goods. As you can see, both would reduce the actual money received in payment of gross sales invoices.

Can A For Profit Business Take A Tax Deduction For Sales Discounts To A Non Profit? How Would You Book That?

Sorta,
You simply recognize less revenue.
So your gross profit = revenue – cost of sales.
And net profit = gross profit – overhead.
You’ve taken a deduction simply by lowering your revenue.