I consider myself fortunate that I received sample policy copies for both BMW's Gold/Platinum coverage as well as the third party packages via Zurich and Wells Fargo.
Completely agree with your 2nd and 3rd points. Your 4th caused me to pause and research the Zurich and Wells plans further ... fortunately, both are ultimately fiscally responsible to back their claims (though technically, they've setup legal entities to protect their total exposure). End of day, I'm not too worried that they're going under.
From comparing the BMW versus 3rd party packages, the one's from Zurich and Wells are much more cost effective, and longer in duration (an additional 2 or 3 years via BMW vs 5 years through Zurich or Wells). Hence, I'm leaning towards a third party package.
Between the two, I'm still undecided (Zurich vs Wells). Compass and EasyCare are not out of the running either, though the dealer rep quoting me a Compass package is taking an inexplicably long time to do so (e.g., 2 days in, still no quote).
For those forum members who have experience with 3rd party packages, any advice? Obvious considerations of what coverages are included/excluded, as well as price ... but aside from those, I'm interested in learning more about the ease (or pain) of filing a claim through any of the aforementioned providers.