Permissible and Impermissible actions in Ihraam

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?

Q: In the days of hajj days, 8, 9, 10 Zul Hijjah, if there is impurity/najasat (urine drops and semen) on the ihraam but the body is clean with valid wudhu, and later while performing tawaf e ziyarat there is impurity/najasat (urine drops and semen) on the clothes, but the body is clean with valid wudhu, will the hajj be valid or not?

Q: I am 55 years old and I have a disability on my left leg due to which I have great difficulty in walking even a few steps. Now I use a leg brace due to which I can walk even 1 km. However, I have to wear a trouser first so that the brace does not damage my skin. What should I do in ihraam?

Q: When performing tawaaf in the state of ihraam, is it permissible to wear socks?

Q: I heard that people don't wear underwear in Hajj. Is that true?

Q: I am planning to go for Hajj in 2020 but not sure what kind of sandal I can wear when I am in ihraam. I found that some of them are saying I have to wear a slipper with the 2 belts (flip flop) without any stitches. Some say that I can wear any kind as long as the back and the front are open and some say that it cannot cover the middle part of the foot. Please  explain to me what kind of footwear I can wear, if possible a picture would be great.

Q:

1. Can I wear sunglasses when making tawaaf for umrah and hajj? 

2. Can I wear perfume at the time of tawaaf for umrah and hajj?

Q: I would like to know what kind of slipper I can wear in the state of ihraam. Is it a must to wear a 2 belt slipper or I can wear the slipper which is open in the front and back?