Is it true that Imam Muhammad ibn Abd al-Wahhab permitted walking with sandals in the mosque and forbade visiting graves?

Imam Muhammad ibn Abd al-Wahhab did not forbid visiting graves; rather, he encouraged it to remember the Hereafter, provided that one adheres to the prescribed Islamic etiquette and the reported supplications. What he did forbid was undertaking journeys specifically to graves, acting upon the hadith, "Journeys should not be undertaken except to three mosques." Nor did he state that it is permissible to walk with sandals in carpeted mosques; rather, he stressed what is consistent with the cleanliness of the mosque. He also did not advocate for a lack of devotion in prayer; instead, he encouraged devotion and magnification of Allah.