I love the color and perspective in this! Great job, it feels really immersive. I especially like how the background objects become hazy as they get further away. I think my only suggestion would be to extend the edges of the frame so that you could see a little more of the sky; I think that would help balance it.
I really like the perspective of this - it's interesting without being disorienting and you did a really great job with it. The light in this is very warm so I think to help balance it out you should emphasize more cool in the shadows. I also think it would be cool to see more details like molding or symbols or something like that on the walls or pillars.
This angle is pretty cool - I should be more bold and try stuff like this. I like how your colors are working together as well (as you may have noticed, I am quite the fan of blue and gold color schemes!). You could try out the other suggestions and see how they look, I think they're good ideas. One thing you could also try would be to cheat the light source a little bit and slightly knock down the highlights on all the walls except for the center wall (with the arch) using a gradient. I think that would create an interesting focal point and make it look more grandiose,