Your not going to like my answer. I apologize. You have been given the best answer already.
Move the location of your pick up to a safer location. All 4 your scenarios fall under a saying we have here here on this site.
Play stupid games in stupid places with stupid people, you will eventually get stupid prizes.
Stupid Games - Doing business in a parking lot in a bad part of town.
Stupid Places - Parking lot in bad part of town.
Stupid people - the criminals and gang bangers.
Stupid prizes. Loss of car at a minimum, loss of freedom and/or life
In no way am I saying you are stupid, or even inferring it. But for a 20 year customer at 1000 pounds a week you are committing an egregious accounting error.
Everyone feel free to zone out. Accounting lecture mode engaged .
There are 2 main ways to account for delivery of goods sold.
FOB Shipping Point - Indicates that the title and responsibility of goods transfer from the seller to the buyer when the goods are placed on a delivery vehicle.
Free on Board - Including or assuming delivery without charge to the buyer’s named destination.
Stores, which is what you are, and customers do not typically use FOB Shipping Point as that involves them paying additional charges for freight charges.
As an example Hanes sends a shipment of clothing to Walmart, Walmart assumes no liability for those clothes until they hit Walmarts dock at one of their warehouses.
So asking your supplier to meet you in a safer location is the best option. Your 4 other options are non starters due to risk.