@aim,
Nice inheritence, aim.
They all look good quality, so whoever collected these had a good eye, imo.
Regarding 8. The four claws on the dragon would strongly suggest that it is Chinese.
Japanese dragons tend to have three claws, "ordinary" Chinese dragons have four, and Chinese Imperial Dragons have five or more.
There are exceptions, but generally the dragons follow these rules.
One other thing I would suggest would be to try and get your hands on any piece of documentary evidence regarding these items. Sales invoices, provenance letters, anything.
This will help tremendously in the future should you decide to sell any of them.