Ordering customizations

I’d like options to delete the “trip fee” line, delete the “i have a coupon” line. And I’d like an option to insert custom lines with amounts for specific clients/companies. And the option to have this “split off amount” be invoiced separately to the company but not the agent. (I have a brokerage as client that pays for a set amount of each photography bill so their agents don’t have to pay it all. I’d like that to be visible so that the total amount that “they pay” is lower and there will be less sticker shock and more chance of bigger orders.