Newbie to RTW travel with a couple of questions for a trip in the fall 08 to spring 09

1) If the Europe air portion is started at LHR & finished at LWG then over land to Asia is that allowed?

2) Want to visit Taj Mahal, realize can't do it on One World, was thinking Air India from Bangkok to New Delhi to Akra return Bangkok?????

3) What problems do you see with the following itinerary?

note land travel LGW-BKK PER-CNS PTY-SJO

YYZ-LHR-CAI-AMM-LGW//BKK-NRT-SIN-DPS-PER//CNS-AKL-HNL-LAX-PTY//SJO-ANC-YYZ

Not sure if I listed that right as there will be stops 4 of the flights but same flight #

Thanks for any responce