Datasheet for TVT14431
It is a thermal fuse but they dont say what type it is. They did not say anything about it being self resetting so i think it is not. If it is not, it might be safe to use

The thin MOV would be TVR14431, same as in the GPT SC9 ELEC surge protector (which uses 3 unprotected MOV's)

Indeed, it is not self-resetting.
But back to the original problem: Is this protector a tickling time bomb?
According to the page 7 of the datasheet the fuse is required. So even when protected, the protection is not qualified to replace the required fusing. Even not in China...

So as in the protector are clearly no fuses, I do consider that as belonging to the "unsafe" category.

The thermal fuse would stop it. If no (if it breaks down), won't it be allready at high enough current to trip the C16 breaker ?

What if the thermal fuse fail to break the eventual higher  current?
What if the pocket designed to suck out the melted metal won't actually suck it out (because they happen to be e.g. contaminated)?
 You would wait a minute with 30A current (before the C16 trip on that)?
It is not rated to be operated without the fuse, so I won't do that, it is really about risking a fire...
The thermal protection in most cases only allow the protected device to continue operating, although not protected anymore. But the "in most cases" is there very important - as in some cases the thermal fuse simply wont be sufficient...