Is the tenant entitled to recover the amounts he was forced to pay and the material and moral damages he incurred due to the landlords' breach of their agreement and their delay in allowing the opening of the shop, and is he permitted to take his right by force or stratagem, or to deputize someone to do so?

If the contract stipulated opening a door and the shop owners reneged, then you have the right to annul the contract. However, if it was merely a promise of permission, then fulfilling it is commendable, and according to the Maliki school, it becomes obligatory if damage results from not fulfilling it. In this case, you have the right to compensation for the damage incurred. A definitive ruling cannot be made without knowing the details of the contract and exactly what transpired. Therefore, one should refer to the court or people of knowledge.