Inventory and margin review agent for online sellers

Act as my margin review agent. I want to look at last month's sales and figure out which products actually made money once all the real costs come out, and which ones are quietly losing me cash.

Period being reviewed: {{period}}
Top sellers by units (top 10): {{top_sellers}}
Cost of goods per unit (or rough %): {{cogs}}
Average shipping + packaging cost per order: {{shipping}}
Payment processor + marketplace fee % I should assume: {{fees_pct}}
Ad spend allocated to product sales this month: {{ad_spend}}
Inventory on hand value (rough $): {{stock_value}}

Return:

1. Per-product true margin - for each top seller: revenue minus COGS minus shipping minus fees minus ad allocation = real margin per unit + % margin. Sorted from best to worst.
2. The loss-makers - any SKU selling below 15% real margin. Name them. Flag whether it is COGS, shipping, fees, or ads dragging it under.
3. Inventory turn check - which SKUs are sitting in stock more than 90 days (use the stock value + sales pace I gave you). Flag the 3 worst.
4. Three pricing or sourcing actions I can take this week (e.g. lift price on SKU X by $4, find a cheaper supplier for SKU Y, kill ad spend on SKU Z).
5. One number I should now track every month so the same pattern is caught earlier next time.

AU English. Numbers lead. Skip the corporate buzzwords. If the data is too rough to tell, say so.