Upvote:1
Are bookings in advance mandatory or can any train be booked at any counter given the 80% pass holder threshold has not been met?
I believe you can just book at the counter.
When I buy a pass, does one segment allow me to travel that one route regardless of price? (e.g. train costs 180$ but I am booking the leg with a segment, hence I pay nothing)
Correct
Does the 45-day limit mean I must complete all 18 legs in 45 days else they will expire?
Correct
When booking a Train Pass I have to specify a pickup date. Must I pick it up that specific day or can it be before that day?
I don't know this one, sorry.
Given I book the Silver Star from Miami to Washington, DC with one segment, could I decide to get off in Orlando, letting the some of my ticket expire, could I rebook the segment (e.g. Orlando to Washington, DC)
If I've understood you correctly, yes. You will obviously spend another segment rebooking later; one trip on one train from origin to destination counts as a segment, so if you get off at an intermediate stop and catch the next train (or another subsequent one), that's a new segment.
I'm not American but I've used a USA Rail pass before.