What should one do if they find it extremely difficult to pronounce the Takbirat al-Ihram and the Basmala for ablution, and are they sinful if the prayer time expires while they are trying to perfect them?

Worrying is one of the worst ailments. Whoever is afflicted by it must strive against their soul and repel it. They should say the opening takbir (Allahu Akbar) for prayer normally, without overthinking, and turn away from the whispers of Satan suggesting that their takbir is not correct. As for saying "Bismillah" at the beginning of wudu' (ablution), it is a sunnah (recommended act), and if one omits it, their wudu' is still valid. If one is overcome by waswas (obsessive whispering) until the prayer time expires, we hope they are not sinful. They must ignore the waswas and strive to repel it.