Is it permissible to perform Tayammum for a month due to a medical condition that requires avoiding water?

Tayammum is permissible so long as the above excuse lasts. And Allah Knows Best.

What is the ruling if someone wipes his head then shaves it - must he repeat it?

If a person performing ablution shaves his head after wiping it during ablution, he is not required to re-wipe his head or repeat the ablution. And Allah the Almighty knows best.

In our region in southern Oman, specifically in the city of Taqah, there is a mosque that they say was built hundreds of years ago. This mosque is surrounded by graves, meaning it is in the middle and the graves are around it. People in our area differ, with some considering it permissible and others considering it forbidden to pray there. Moreover, my grandmother saw in a dream that she entered this mosque..."

 

What is the ruling on istibra' and how is it performed?

Istibra' (cleansing from urine) is recommended. It is for a person to ensure that nothing remains of urine in its passage before performing istinja'. Its method is: to clear the throat (or cough slightly), shake the penis (meaning to pass fingers along it to expel any remaining urine if needed), and walk a few steps to the extent that one thinks nothing of urine remains if walking is needed. Each person knows his own nature best. The preferred opinion is that this differs among people. The objective is for one to think that nothing remains in the urinary passage that he fears will exit later. And Allah the Almighty knows best.