I found this article really interesting.
I will add some of my own advice to your own valuable advice above:
After having sold a few thousand products via Amazon, I would recommend trying to ship and fulfill yourself, it's not rocket science. You will save $10 per product. You'll find that spending an hour Packaging and shipping 10 items will quickly pay for your time. Request the supplier to package the goods in untaped individual boxes. This cost adds pennies per product and saves you a lot here when reshipping.
Your points about doing QA in China is very valid, Alibaba even offers reputable QA inspectors as an upsell to your product purchase.
It may be worthwhile to find something that is selling well and list it New below the cost of the "sold by Amazon" version. You'd be surprised how many customers take the cheapest option over the fba variant (as long as shipping is quick and free). This way you do 0 marketing.
Marketing is important, but once you have critical mass and a good product you can relax a bit and coast off the reviews and Amazon algorithm to get some residual traffic.
Put up YouTube videos. These are the first things that come up in the search results when somebody searches for your product, free SEO and marketing. They will show the product in greater detail than Amazon product images and consumers will feel good seeing that it exists outside of Amazon.
Source premium packaging from other manufacturers on Alibaba. This can be very cheap and you can even cheat and send it to your product manufacturer for pre-packaging and ship it all together. The same notes about QA inspection apply. I've done this for complementary products like cables and bags.
Consider registering your trade mark, this is cheap and prevents your supplier or one of their other clients (ie their buddies) from at least copying it straight up and selling it on other marketplaces once you've done the hard work of making a coherent product page and videos.
Now, the hard part - customer service. Making sure you are responsive, that you're messaging properly post-sale and post-delivery and that you are responsive to Amazon's requests as well.
Doing your own fulfillment is a learning curve, and maybe you want to learn the ropes with FBA before jumping in, but really, giving >100% of your margin to Amazon for them to pick-and-ship is a bit heavy. At minimum I would list the product for FBA and new with free shipping at -5% so you can recoup a bit on those "direct" sales.
Most items cost less than $10 for FBA to ship. FBA fees for a 13 pound item is just under $10. There's no way you're getting $10 in savings unless you're doing massive volume and shipping really massive items (like 50LB) or with large dimensional weights
You can easily ship a light purse in domestic USA for $5 if you have a business shipping account with a carrier. Making $8 with FBA per sale vs $16 by shipping yourself when you already have boxes is pretty simple.
This 4 piece purse set is only $7.01 in fulfillment fees: