Allow me to answer parts of your dillema that I know I can. More experienced FT'ers will chime in perhaps for the rest.
Originally Posted by jayzee9
I would like to not use the ORD-AUS segment, and have been told by my travel agent if I miss that flight, they probably won't cancel the rest of my itinerary.
- this is absolutely NOT true. It's called 'throw-away ticketing' and it's strictly forbidden as well as enforced by the airlines. SABRE (AA's reservation system) will automatically cancel any remaining segments on your reservation when it detects that you did that. This rule is in place to prevent people that want to go to XXX from buying AAA-XXX-YYY and dropping the last segment, versus just buying AAA-YYY which sometimes can be more expensive...
Originally Posted by jayzee9
I have looked on the web and the flight is:
F4 A0 Y3 B3 K0 H0 M0 G0 W0 V0 L0 S0 N0 Q0 O0
1. Does this mean it's oversold? The seat map shows three seats unassigned in coach.
2. Is there a chance I would get bumped?
the flight is not yet quite oversold as there are still 3 seats left for sale. if it was 0 across the board then it would've been oversold. Although it might become oversold between now and the date of your flight. You will probably not be bumped unless you ask the GA to put you on the volunteer list, since you are PLT.
Bottom line is, if you need to fly LGA-ORD and return AUS-LGA then you need to have your travel agent ticket it properly. Again, your reservation WILL be cancelled if you deliberately miss a segment - your TA is WRONG.