Is it correct to say that Ibn Taymiyyah permits receiving reward from Allah for performing Bid'ah (innovations in religious matters), and to what extent is it valid for some to use Ibn Taymiyyah's words in "Iqtidha' As-Sirat Al-Mustaqim" to justify Mawlid celebrations and other Bid'ah?

Celebrating the Prophet's Birthday (Mawlid) is an innovation (bid'ah), and the religious texts and statements of scholars indicate this. Sheikh al-Islam Ibn Taymiyyah considers the Mawlid to be an innovation, and every innovation is a misguidance. He affirms that an ignorant person may be rewarded for their good intention and love for the Prophet, peace and blessings be upon him, but not for the innovation itself. As for someone who knows it is an innovation, they are sinful, have no excuse, and their good intention will not benefit them.