I would agree with the previous comments. A plain fabric will enhance your wallpaper as a feature. I have a similar look at home and used plain curtains to make the wall paper really stand out. If you opt for a lighter weight fabric you could always use an interlining to ensure you don't compromise on warmth. Interlining is a padding, it sits between your curtain and curtain lining and comes in different densities, I used an interlining that was attached to my curtain lining for ease. Dianne PS please ignore the bunting, its not a permanent feature :-)

Microcement would give the ideal look you are after with the protection coat making it safe to have around your fireplace, it's not cheap but it's full application has only 3-5mm thickness whereas with actual concrete you'd need it to be quite thick and there's risk of it cracking in places. Hope this helps.

The challenge with a more ramdom design is you most likely end up going down this type of route https://www.iwantwallpaper.co.uk/superfresco-easy-super-fresco-easy-daintree-taupe-rose-gold-palm-leaf-metallic-shimmer-wallpaper-p6438 But it still has an element of pattern. Any pattern that is going to be geometric will look like a block pattern. Or you could look at something like this: https://www.ilovewallpaper.co.uk/wallpaper-c1/patterned-wallpaper-c2/wallis-bark-texture-wallpaper-taupe-p7591

Need help with the feature wall for the lounge. The tv will be on the wall so i wanted something dark so the tv doesn't stand out and give it a more cosy feel as it's an open plan kitchen/dinner/lounge. Initially we wanted the acoustic panels either oakor concrete grey but then decided to paint due to costs but can't decide on the colour. Did look at wallpaper panel effect and textured wallpaper but didn't find anything we liked. We have a navy blue snug sofa and we wanted to paint to wall blue but will the sofa just blend in with the wall? The other option is grey or a bluey gery. It's an open plan area and the kitchen is concrete grey. Any suggestions/feedback is appreciated. Thanks