3) 0.4-0.5W / cm^2 will heat it up quickly and allow the PID control to regulate it easily. That bed size is small and doesn't need a very high powered heater. You have 169 cm^2 so I'd look for a heater that's around 75W. With such a low powered heater you could just run it from the DC supply and save the messing around with line power. The controller board MOSFETs should easily handle switching power to that load.
The internal fuse will be rated for the maximum power the PSU can supply, you should add an own fuse for the heat bed that is rated for it, the internal fuse of the PSU might set in to late.Quote
So, checking with Mean Well if that power supply has a fuse, if it does, I needn't add one correct? If it doesn't I'll add one.