No-name brand using CMC is not surprising.
Using fake CMC (doubly bad media) would also not be surprising.
On a good day, those are marginal discs, with the more common issue being edge burning. So you're best off not using the discs for more than 4gb worth of data. Every 100mb after it multiplies the odds it'll be a coaster.
The funny-looking areas are either bad dye or failed bonding/glue. An attach photo would help.
Nope, not reassuring. Some discs are so terrible that you'd do better to stick a waffle in the drive. The odds of a successful burn are the same.