Prayer

Allahumma ihdini feeman hadayta wa ‘aafini feeman ‘aafayta wa tawallani feeman tawallayta wa baarik li feema a’tayta, wa qini sharra ma qadayta , fa innaka taqdi wa la yuqda ‘alayk, wa innahu laa yadhillu man waalayta wa laa ya’izzu man ‘aadayta, tabaarakta Rabbana wa ta’aalayta la munji minka illa ilayk

This is not correct. If the Istikhara was done and one felt good and went on with it, this means that Allah choose for you this thing and there is good in it for you. However, whatever happens afterward is good for you but you may fail to see it as Allah has things store […]

It is Sunnah and not mandatory.

If you are referring to 3 rak’ah witr, it is not permissible to sit in the 1st tashahud as in Maghrib.

It is Sunnah but it is not mandatory.

The Sunnah is to point the finger and moving it in its place.

No, it is not.

Should start with Fatiha.

There is no expiation. If she didn’t recite the tahiyat, her prayer is invalid unless she is a new revert and doesn’t know it.

He must pray Fajar as soon as he wakes up.