You do know that you can buy tickets at aa.com for other airlines.

I have had the EXP desk reroute me on other carriers by phone during irrops but always have to go up to an aa desk to get the boarding pass/ticket.

I still am confused by the not getting everything in one sweep. The VDB voucher receipt has to be signed before the voucher is given. To me this is the same as volunteering giving up your seat (exit row for example) than finding out that you are not needed and somebody else has your primo seat and you now have a middle in the back

If you have not played the VDB game than you need to study it before jumping in, Here is one about seats from a few months ago. VDB: Why I don't volunteer to bump - AA doesn't like me or am I doing something wrong

An advanced search for "VDB" will bring up countless woes and whoohoos. Yes, you can learn a lot from someone doing it right and even more from someone doing it wrong. YMMV but my advice is the same as I would give to any inexperienced swimmer - don't jump in the deep end until you have tried it in the shallow part first.