Salaah

Mustahab times for salaah

Q:

1. If the asr time starts at 3.57 and sun sets is at 5.32, what is the mustahab time to perform asr and when does the makrooh time start?

2. If fajr starts at 5.25 and magrib starts at 5.34 what is the mustahab time to pray esha?

3. My salah app shows that sehri or tahajjud time ends at 5.16 and fajr starts at 5.25, Can I pray tahajjud between this time? 

Joining salaahs

Q: If one has oral surgery due to having a wisdom tooth removed, and therefore has constant bleeding in their mouth for days, are they allowed to join prayers? If so how long are they allowed to join prayers? Is it until the pain ends or until the bleeding stops?

Performing qadha salaah

Q: I started praying five times a day. Now I realize that I lost almost 25 years of praying. So according to this I was praying all this month but not regularly so Ramadan regularly praying almost praying for other days as well morning. Was it as well so I feel almost 10 years has been done now remaining 15 years prayers out there so I calculated for 15 years. So I need to clear 5475 pending prayers it is just an approximately figure please suggest advise me on this one

Salaah time expiring while one is performing Salaah

Q: If salah was delayed nearing to the end of its time and the takbeer for commencing the salah was made within the time, for example within dhuhr time, however, the salah was completed when asr time set in then will the salah be counted as a qadha salah or will it officially count and also will this count as missing salah within its time thus meaning one is sinful or will it be sinful for other reasons such as the sin for delaying and is there a difference in severity between these two sins?