Permissible and Impermissible actions in Ihraam

Q: I am traveling to Musjid Al Aqsa and intend to make niyyat and wear ihraam from there to perform my umrah. 

Can I vape while in Ihraam due to the lengthy time as it will be about 20 hours?

Q: Can a hernia patient wear underwear in ihraam?

Q: My father has a small problem with old age and urine drops. He says straight after he goes to the toilet, about 5 or 10 mins after, he has some trouble with few drops. Then it subsides. 

He usually uses tissue with his underwear for a few minutes after going to the bathroom in case any drops come out and then discards it a short while later. 

He's concerned with ihraam and how would he manage. 

What would be suggested? Is there an option to wear underwear and pay damm? Or is there any alternative.

Q: Is it permissible to scent the ihraam towel before entering into the state of ihraam?

Q: My hair is very thin, especially my beard hair. If I make wudhu and do khilaal, then sometimes, few hairs fall off. 

I'm planning to do umrah inshallah. My question is that if I am in the state of ihraam and hair falls off accidentally while making wudhu etc., not on purpose, then will there be damm or anything necessary?

Q: Can one perform Umrah with one of those umbrellas that has an elasticated band and you can wear it on your head leaving your hands free... especially when the temperature exceeds 30+ degrees?

Q: If a person is in Hajj with his ihraam on and his friend back in South Africa phones him requesting to borrow his hunting rifle to hunt with, will it be permissible for him to lend the rifle to his friend?

Q: If a person forgets to remove his underwear after making intention for Ihraam, what should he do?

Q: While performing umrah, can ladies wear contact lenses? 

Q: As the Kabah Shareef has a scent/itr, is it permissible to touch the Kabah Shareef or Hajr-e-Aswad while in ihraam?