Noob power supply build

So I had heard from multiple sources that the Bento Box's (cheap 500 series rack)  main issues were from the Cheap power supply inside the unit.    So I decided instead of building a complete new unit I would replace the power supply in mine with an external supply via a JLM powerstation.  So I am using a 5 pin XLR to transfer power from the PS to the box. 

My question is that I would like to add a switch on the front of the rack so I can switch it off and not have to turn it off at the power supply.  Can i put a swith on the +16 and -16 rails from the PS and when they are turned off not hurt anything having the 48V rail  active? 

Is it going to hurt the PS to have it on all the time?

If all else fails I will just turn it off via the Power supply but I was hoping to be able to implement the switch on the rack. 

Thank you for your help,
Dustin C.

Any help?

I don't have anything good to say about your plan but you asked so ...

It just doesn't make sense. You're going to leave the PS on but cut off just +-16V and not 48V at the 500 rack? No.

Switch power at the AC source.

Just get one of those Furman style rack mount power conditioners (or a simple surge protector since those power conditioners are largely BS) and use it's power switch to switch everything on / off.

It's not a good idea to leave a PSU switched on without any load on it. 

Yea I had a feeling this was not going to work out too well.  But for some reason looking at the Total Audio Control Racks,  It appears he has a switch on the rack but an external power supply so I thought this may have been a solution.  He is probably using some relay circuit to turn the entire psu off I'm guessing.

I will just turn it on/off with the floor power supply and not worry about the switch.

One other question,  Does the rack need to be chassis grounded?  Or just the PSU?  I assume it is not necessary to have the rack grounded because of the lack of high voltage rails inside the Rack. 
I can easily add it but just wondering if it is actually necessary?  What is the proper procedure with an external power supply?

Thank you all,  I realize each time a try a new project of how much I have no clue about

You should ground the rack chassis so it isnt "floating".