If you have Civ IV + BTS (no Warlords), you get ALL the features and gameplay of both BTS and Warlords expansions. The ONLY thing you miss is the Warlords scenarios.
You can play with no espionage with the new option "No Espionage" added in the latest BTS patch.
You can play with no AP (Apostolic Palace) by unchecking Diplomatic Victory.
Well, if you want to play with the Warlords rules (say, having great generals and the Warlords leaders but no espionage and no AP), or maybe you want to play the Warlords Game of the Month), you'll need to own the Warlords expansion.
You can play with no espionage with the new option "No Espionage" added in the latest BTS patch.
You can play with no AP (Apostolic Palace) by unchecking Diplomatic Victory.