My two cents:
I do think all chocolate, including bulk, is tempered. Otherwise, the surface of these chocolates would be covered in swirls and light patches. If you want to see what untempered chocolate looks like, melt a little in a bowl, being careful not to temper it (no seeding), and see what it looks like after it’s fully set. However, bulk chocolates may be more prone to conditions during storage and transport that cause it to lose its temper, I’ve definitely seen some bulk products that showed signs of too much temp fluctuation. Also, there are different methods of tempering- some are fast, easy and produce a reasonably good result (but may have a duller surface and be a little softer), while others are more involved but produce the best possible snap and shine.
One issue I have noticed lately with bulk chocolate- especially unsweetened, is that it is a bit more grainy, with particle size that can be detected/felt when eating.
Cocoa butter content varies widely from brand to brand and within brands, there are no real assumptions that can be made. If you want a product with a high cocoa butter content, you can read fat content labels (Green & Black’s 85% has a higher cocoa butter content than its other formulas) or buy couverture, which is designed specifically to be a high-quality coating/dipping chocolate.