My question is if a player has the government type monarchy and gets two actions with the capital, can the first action be used to start a building program and the second to produce a building, unit, or wonder?

On page 7 of Wisdom and Warfare it says, start a building program is a fourth city action. So it looks like start a building program is separate from producing a building, unit, or wonder action.

It seems on the face of it to be having your cake and eating it too. In game we couldn’t find any rule against it. We zoomed through to the modern wonders very fast! It caused a buying frenzy after the first two ancient wonders were purchased.

Withoutr looking deeper into it myself I'd have to say it seems like a legit way of doing it. might lean towards being OP but then again, everyone can do it...

OK, it seems legit as long as you place the built wonders in your capital, which means replacing the old one

OK, it seems legit as long as you place the built wonders in your capital, which means replacing the old one

This. Only one wonder per city. So you'd have to keep replacing the old ones with new ones. Could be effective if you're trying to get a specific wonder.