I'm building a consumer facing prompt manager (https://promptfolder.com/ - no API yet), but I've looked at most of the other tools... unfortunately I haven't seen anything that is a solid fit for what you're looking for.
You might want to contact the devs behind PromptPal (https://github.com/PromptPal/PromptPal), they seem to be some of the more technically advanced and fast moving people building in this area... maybe they can hack something together for you.
OP here - no. "Shipped and sold by Amazon.com" items can be sent to Amazon's fulfillment centers by anyone with a Vendor Central account. There is still plenty of fraud going on there.
In general I would say it is safer than an FBA or FBM offer, but not totally safe.
Vendor accounts are highly sought after by black-hatters because:
1. It's much harder to track down shenanigans you run on them (since as you said the only public seller info is "Amazon")
2. They generally have higher authority for editing listings, so if you want to change a competitor's images it's more likely to stick from a vendor account
Sounds like there is maybe some code debt involved!