Yes prayer becomes invalid if we don't use turbah. It's an obligation to use it, as I mentioned before the prophet and the members of ahlbait did not perform their prayers on carpets, but on soil or sand. After the martyrdom of Imam Hussein AS the soil of Karbala was preferred, so these stones...
It should also be added that Khilafate was abolished by Mustafa Kemal Atatürk, so in our opinion it could not be divine if a human-being was able to destroy it.
There is no succession nowadays, we believe in the coming of our last Imam(Imam Mahdi), the Shiite scholars who exist nowadays studied in Islamic schools and through Ayatollah Khomeni the system of Wilayat al faqih which is basically a guardianship Islamic jurists, who discuss religious matters...
This is YOUR community's belief, but NOT ours and we have a very different opinion, based on hadeeth.
What I find funny is how non-Shiites always claim how succession should not be based on descendancy yet have no issue with the fact that Muawiya chose his OWN son Yazid to become his...
Look what that Ahmadi typed?! What kind of qualities did the first 3 caliphs have? Abu Bakr took away Syeda Fatima's heritage, Umer pushed a burning door against her, Uthman appointed his family members as successor's leading to Muawiya becoming caliph and subsequently to Yazid's rule which...
It's not about them being descendants, it is about their deeds and their character and pre-dominantly about the fact that we believe Imam Ali AS was chosen by Allah swt as the true successor on the day of ghadeer khum.
You cannot get a Quran that "agrees" with any interpretation of Islam, the only thing you can to is get a tafsir(interpretation) according to Shia scholars and the link above is one of the most well-known ones, there is better ones out there, however most of them are not translated into any...