Hi CC23,
Ryan seems to be the only person anyone deals with, so if he seems pre-occupied that's probably because he's so busy, but he always does have time for you.
Yes I would call him in one week to check that your medicals are okay.
Yes it is true that they give you flight details a few days prior to flying out, but the date you leave will be discussed prior with Ryan and also the date you start training will be discussed with Ryan prior, so you kind of have a pretty good idea what day you're leaving anyway.
I didn't resign from my current employment until I received the contract and it was signed and confirmed that EY received it. I also contacted Ryan and asked if I definately had the job and that I could resign, just to make sure.
You will be contacted via telephone to discuss dates and your flight details are confirmed via email a few days prior.
I hope this helps you, if you need anymore help let me know and I'll do my best.
TanyaD