Hi, my desktop's internal drive broke. So I want to run it from an external drive. I have purchased a drive (Seagate expansion 500 GB, USB powered). So will I damage the drive if keep it always plugged in (as I will be running my OS from it)?. Will the manufacturer deny the warranty looking at "power on hours" in case of damage? And finally, will my computer be slower than one which boots from an internal IDE drive?

My computer is usually unattended, just downloading stuff. It's max uptime will be < 15 hrs.