The only part that's problematic is physically getting hold of the tickets - you need the credit card you booked with to do this, normally (and officially). I've managed to get them from the station before, by asking and giving my name and address, but I don't think this is the 'proper' way of doing it, so I wouldn't count on it.

Once printed and in your hands, anybody can use them, even if they're officially non-transferable. On machine-printed online tickets, there will be a name on them, but this is the name of the person booking, not necessarily the person travelling.

So, if you have them physically, you're fine. If you don't, it could be tricky.