Pictures

Is there another area nearby your venue within a short 5-10 minute drive that would be more suitable for pictures? If so, you could rent a bus or limo to drive your family and wedding party over to that location for pictures after the ceremony, while your guests are at cocktail hour.

Is there an area outside ?

I would discuss your concerns with your photographer. I would keep all photography, especially groups, at the same location as ceremony/reception if only to maximize photography time.
A seasoned professional photographer will know how to handle your concerns.
Best wishes

Discuss this with your photographer- let him know your concerns. They’re the professionals & can come up with amazing ideas.

Maybe you can rent a nice backdrop or make one. We are making a photo spot with the flower columns from the ceremony. Also don't stress it much, your photographer should have an eye for this and should be able to find decent spacing for your guys. They also have software that can edit your background.

Can you just decorate the venue how you want to make the drab areas look better?