My house was built in the 80's and is very small. The living and dining area is basically one space. "Behind" the living area is a small space with access to the backyard. Between this small space and the main living area is a very ugly fireplace and coat closet. We would very much like to remove the fireplace (we live in Houston and never use it) and the wall, closet, etc. in order to open up the living area. My main concern is whether the wall bears any weight. You can walk all the way around the fireplace/closet "enclosure". In other words, it's in the middle of the space and doesn't connect to any exterior walls. There is what looks like a beam across this ceiling above the fireplace that I'm guessing is in place of a load bearing wall. I have attached pics. With the vaulted ceiling and slope of the roof, it's virtually impossible to access this area in the attic and the house sits on a slab so no crawl space. How do I figure out if it's structurally safe to remove the fireplace and closet? Are there any other things we should take into consideration?

That does appear to be a load carrying beam up top. It may carry all of the load or you may have a verticle support beam holding up the center of the over head beam. What is directly below that fireplace and closet? Is there a support beam beneath in the basement or crawl?

The house is on a slab foundation. There is no crawlspace or basement.

Then you must determine if there is a verticle support column inside one of the walls directly below that horizontal beam in the ceiling. This may require some demo work so go slow in case you find a beam and have to reconstruct the walls

Great. Thank you so much! Any suggestions on refinishing the ceiling in that area? Is it even possible to match the old "popcorn" blown on stuff? I hate it but it's all over my house and I just don't even have the energy to tackle a vaulted ceiling! :)

Trying to match pop corn is like finding chickens teeth, not easy. I'd hire that part out