I have the cheaper version and bought it used so I wouldn't really mind if it died on me - as long as it don't bring my Grados with it.
Everytime I turn it on There's that loud popping noise which I have to unplug the headphones for (i guess)...
I also use it with gain set on the PC. Would this strain it less or does it actually push it harder than it would if I were to set the volume on the device?
The manual has explicit warnings in it to unplug any headphones, or turn off any amps/preamps prior to powering on/off to mitigate damage to other equipment, so it is definitely a good habit to get into.
To my knowledge having the Volume Setting setup one way or the other does not cause the Pulse any undue strain, it just uses different logic for processing.