Ye Olde Inn

We have into the french edition a lot of errors into the maps,missing traps and secret door locations !
We also do not have something to buy between quests !
The rule book says as "the return of the witch lord" one that players are walking deeper & deeper so cannot purchase things and come back to town.

I believe there is an optional rule in the Elf and Barbarian Packs that talks about not being able to journey to the shops between quests.

Yep.
They say at the begining of the rule/quest book that you have to play all those quests one after one without buying something between like the 3 last quests of the main game adventures.

The last three Quests in your Game System are played without players being able to visit the shops? That's a cool idea. If I were to play the Quest Packs like that, I would certainly combine those three as well. It makes sense that they can't buy stuff in the quest packs between quests, but the difficulty might be extreme with North American stats for Monsters. Especially when dealing with Polar Warbears and Yeti. I would put more pressure on Heroes to search for treasure though.