I have a desktop machine that has not been turned off or rebooted for more than 3 months. I have a laptop that has not been turned off, although it goes to sleep when you close the lid, for about a month. My desktop is always on because it is always working. I never turn my laptop off because I'm on it all day and it's charging (and sleeping) when I sleep.
OK, here are my specs:
27" late 2012 iMac
Quad core i7
24 GB 160MHz RAM
GeForce GTX 680MX 2GB graphics
1 TB Fusion drive
I usually run renders on my computer for days on end. When i'm working on a project I make sure that my computer doesn't have time to rest.
Computers don't have duty cycles. You can run into overheating issues, but from the looks of your specs, that shouldn't be a problem. If your computer is creating lots of heat and that is bothering your family, then I guess they have a right to complain. But no, you are in no way ruining your computer. COMPUTERS HAVE NO DUTY CYCLE
Actually, turning computers off and on again over and over is worse for them then leaving them on. Metal expands and contracts with changes in temperature. If it stays on and warm, there won't be much change. However if it's on hot and off cold over and over, you're more likely that the internal components will eventually break apart. That's a little dramaticly worded, but you understand my meaning. Rebooting every once in a while is good, but leaving the machine on is arguably better for it. I've never worked at a professional place where machines were turned off (except for a place that had some big Green initiative, but that ended up getting quashed).
I don't think that the heat inside a computer isn't enough for that to happen over the usual lifetime of a computer.
Come to think of it, I NEVER turn my computer off. It's in my room, and I just put it to sleep at night.