IMO, for a bochur traveling overseas:
1: one way ticket so you can choose when he comes home
2: Do direct – stopover not worth the $ and time especially because he’s tight on time and this is last minute. Lost luggage is normal for stopovers- he doesnt wanna start the zman without clean clothes.
3: if you are doing a stopover, make it London and NOT moscow. ( i know tickets are cheaper. it’s part of the expense.) 1.45 is too short (delays are regular) and 7 is way too long ( minyan, food, etc…)
4: it would be great if you get the airport closest to you but dont say no to a flight if the price and timing is good but the airport isnt.
btw, see how other bochurim are traveling to that yeshiva. he can pair up to share a taxi once he gets there.
* Make sure he has medical insurance there!! a must!!! fairly easy to apply for kupat cholim or me’uchedet. Dont delay.
* You should have a responsible adult there who knows English (so you can talk to them) and Hebrew (so they can talk to people you cant) who your son can call 24 hours a day (7 hour difference between US and Israel) for emergencies. this is in addition to whoever they have in Yeshiva. I can’t stress this enough.