I think you need a new mantle and hearth. Your mantle needs to be chunkier and extend all the way across the fireplace - just one solid piece of wood with no trim or fluting. The hearth needs to be a solid piece of stone as well - the different pieces make it look dated. As far as the tv, that is personal preference. I am not a fan - a fireplace is such an opportunity to make a lovely design statement in your room and a tv is unfortunately just a big black box. But sometimes it is the only option. I like your stone and I think it would look great updated with a new hearth and mantle and some decorative pieces. i

I most definitely wouldn't paint that stone, that looks good and probably goes very well with rustic character of the house. It's stone, it has character..if the character suits the house and you like it, you work with it. If it doesn't, then it's a different story. Then I'd weigh my options, and might decide to forego the stone at all, rather than painting it. But I for sure wouldn't paint because somebody told me I should. I'd listen to their reasoning maybe, if there was any, and draw my conclusions. What were the reasons for this suggestion? Besides modernizing, which I fail to understand in this context?

Chunkier longer mantel might work better indeed

I wouldn't put Tv up there-not ideal viewing position, too high usually...and you have another spot fot TV. I'd put there art I love, lean one big piece or maybe couple different even, and wouldn't hurry too much either until I find something I really love.I don't know what colors it will be:) You'll know when you see it. I'd love oil paintings up there, but maybe you fall in love with bright prints, or etchings, or..

You didn't ask about your window, but I'd be interested to see it..is it the only window in the room? Maybe the rod can go higher and it can take two panels? Or maybe a shade would work better? If the walls stay blue I'd go with panels that are ligher and either have blue in their patter, or blend more.

What are your favorite colors? Were the walls painted by you, or by previous owners?

I can't see all the sofa (or all the room, for that matter, but couple throw pillows and a throw that have in them colors that you like will bring more texture and coziness. I might add something knitted, etc. Also add ligher/brighter tones. Plants if there's enough light. I have a feeling that photo makes room darker than it is.

Congratulations on your new house! Always takes time to make it yours, that's normal. If you want to share more pics/angles of the room, we might be able to give better suggestions(if you're interested to hear them, of course)

I wouldn’t paint it, the color variations of the stone are so beautiful and interesting. And since you like rustic, it’s perfect.

I’d do art above the mantel. Search for something you really love — it doesn’t need to match other decor.