yes
yes
and yes
specifics abound in the various threads here, but it is definitely not all bad. Many of us are vaping happy on kit we bought from a chinese online site, and there are an equal number going through paypal refunds for missing parcels, items wrongly received, items received but faulty etc.
for some sites, the products go out of stock quickly, and the next batch may have unique issues, so it isnt even always enough to say "i bought widget xyz from site abc and it is fine" because the one you buy may have slight enhancements, or even flaws, compared to the one the other chap bought. So we share info, and stick together