That seller did not upload a picture of the title screen. What you see is the splash screen that appears before each stage, which looks normal to me. It's worth mentioning that taizou dumped this game from a Singaporean cart that has the same design as that one

I've seen stuff by PR Trans make it onto pirate carts (Pikachu Land is by them, and sometimes credtis them even on pirate carts). Not sure about unmodified stuff from them though. I'd say that I don't remember stuff on the matter clearly enough that I'd advise putting it on the wiki. Also gotta factor in that these translations went through multiple revisions

None of the carts in this thread look like Ka Sheng carts. The game has multiple publishers

A lot of the members of BGC spend more time on the discord server than the forums. He never stopped being active over there. If you saw that document I posted on 2024 highlights for BGC, his name pops up a few times for some pretty cool discoveries he helped make

This is my favorite thing I've gotten to share here so far. It's a ROM dump of a prototype copy of A-Force by Sachen I found a few months back. Technically this is the Mega Duck version, but Mega Duck games are mostly the same as Gameboy games at a programming level. I shipped it out to Sean Riddle who was able to dump it (he redumped a few times to make sure it is a good dump) and gave me some info on his findings:

"The EPROM is connected directly to the cart data bus D0-D7 and the cart address bus A0-A14.  Chip enable is connected to cart A15, so the EPROM outputs are tri-stated for addresses $8000-$FFFF.  Output enable is connected to /RD.  EPROM A15 is connected to the MC14174B HEX Type D Flip Flop’s output 0.  The flip flop’s input 0 is connected to data bus D0, and the clock input is tied low and connected via a diode OR gate to /WR and A14.  So writes with A14 low will latch data bit 0 for use as EPROM A15.  The flip flop’s /reset signal is connected to the cart’s /RST pad so that the game starts up in bank 0.  The other 5 flip flops are unused.

This 32K bank switching is different from the 16K bank switching used in the production carts.  That likely explains why large blocks of code have been shuffled around."

Interestingly the shell for the cart appears to use the design for Mega Duck carts that is seen in old advertisements (light colored plastic and slants on the sides of the cart)

I don't think it is. The description I heard for Blood of Jurassic is that it has the same Shanghai Paradise crest that Super Hang On has, as well as the ID code GD-98 on the sticker

Do you know who can fix these?

I currently do not have any contacts that can help you. Sorry

To answer your question on whether or not unofficial Taiwanese Famicom games were sold in Europe, the answer is yes. Some was even sold in Western Europe and Canada. I would say those are not good locations to search through though. Not because the carts aren't there, but because you're going to mostly see official carts, so you'll be sifting through a bunch of stuff you don't want. Since you have a pretty short list of things you are looking for I would recommend taking your time when it comes to searching so you don't wind up overpaying a ton or get stuck using expensive shopping agents