tashahhud

As-salamu `alaykum. If I forgot to do something while praying, for example, sitting in the second rak`ah or any other thing that might be forgotten while praying, what should I do? Should I start all over again?

Concerning the Salah, is it obligatory to pray exactly how the Prophet (PBUH) prayed. For example, when I'm sitting to do the tashahood, I am unable to sit how the Prophet sat because it is uncomfortable and difficult. Is this okay to not sit like that or must I learn to sit how the Prophet sat ? Thank you

From  Ismail Patel Subject  About aqidah Message TextDear sir, Assalamo Alaykum, while performing salaat(Namaz), we recite attahiyato lillahe... in which we recite assalamo alayka ayyohannabiyyo, meaning "ya nabi, peace(salaam) be upon you", then why is there so much unnecessary debate on whether our prophet is present everywhere or not ? The word alaa in arabic is a root word stating "upon" Now if ha is joined after alaa, it becomes alayhe meaning "upon him" Hence alayka word used in attahiyaat clearly implies us that nabi is in front of you when you are praying salaat. In this respect sunni wal jamaat believing in sufism is true in their aqidah. Please reply me soon.