I do not understand how the student and 5# tickets work. On their website I see seats for like 50# but we are traveling with my son who is a student and would qualify for the 5# tickets. But when I put in the code, I get a whole different set of tickets available. So do we buy 2 at the higher price and let him buy 1 at the lower price and then not sit near each other? And how do the standing room only tickets work. Rick's book says stuff about standing at the stage, but wouldn't that block people in the 50# seats?
I don't know about your general booking issues: I would wait for UK office hours and call the RSC box office yourself. I don't think any RSC theatres have standing tickets, though. Are you thinking about the Globe in London? It's not a good idea to get them mixed up given the distance between them. (One of my most embarrassing moments as a volunteer at the Globe was when someone turned up with tickets for the Royal Shakespeare Theatre in Stratford: when I explained that this wasn't the RSC their response was "Stratford's on the tube, isn't it?)
See the following page, specifically the section 'Ticket discounts: 16 - 25 year olds': http://www.rsc.org.uk/buy-tickets/stratford-prices.aspx I was at the RSC in Stratford last year for a fabulous production of Julius Caesar. If possible, go a little early and browse in the great bookshop before going in to your seats. Enjoy!