Not exactly. Chandragupta(Founder) was a Hindu that converted to Jainism. Chankya the prime minister was a Hindu. Chandragupta's son was a Hindu. Ashoka was a Hindu that converted to Buddhism. But yeah, Ashoka made it a mission to spread Buddhism. And those Hindu temples shouldn't be used as references for this period in my opinion.
I also think that's the best one, because of the wood. Don't put a Buddha statue in this period. If you notice, all of the reliefs are about Buddha's life, but they'll never show his figure. It's a later development. Maybe some sort of fire alter.
Lordgood. I'm not talking about the different shape of the columns. I'm talking about how it looks it's like a relief to the building. It's a Roman style I believe. That became more popular in the renaissance. This is more better. The column is complete looking.
I feel like you guys should use a lot more wood. Such quasi columns don't really exist in India. It's more of a European thing. Even when they are cutting through rock, they have the columns more like your first model.
Those reliefs are from the Mauryans direct successors btw. Not from the Mauryans themselves, but stylistically things didn't change much between its successors and the Mauryas.