mounting tv to wall

Hi all - first time posting so hopefully this is the right place! I'm trying to drill some holes (just moved into new rental property) to mount our TV. I initially drilled smaller holes but realised there was plasterboard and then an air gap and then what appeared to be brick or mortar? I...

Thinking about mounting our TV on our chimney breast and would like to ideally run the cables through the breast and out to one side of the alcoves. I'm just wondering what the best approach to this was and if it would cause any structural issues? Here's the chimney breast as it stands - red...

I am have a few concerns regarding mounting my TV. I am in a 1 year old new build with plasterboard walls. My stud and power lead detector is flagging up studs or power on almost every single part of the wall I want to put it on. Behind the wall is breeze block and then nothing as I am end of...