@valfar
I'm not really an electronics-type person as I don't have the knowledge to calculate values, etc. But I believe that you need to choose a high enough rated switch, because if you don't and you slide the switch across, the current will spark across the gap as the switch slides together and weld itself shut, maybe damaging components.
Maybe you can open a switch up and thicken some wire inside to increase this? I've not looked inside one yet so not sure what's in them. I initially bought a 1amp switch but it turned out to be physically huge and there was no chance I would get it to fit the case. I've not seen any the right size rated higher than 500ma.
The switches in the wiki are rated 500ma @50v so I'm assuming this means they can take an initial shunt of 500ma? But as that is for 50v, I don't know how you scale that figure for 5v. Does that change the amp rating (50ma perhaps?)?
In regards to this banggood power board, if it was me, with a minimum power build, I'd wire the switch in the way I drew it here:
http://www.sudomod.com/forum/viewtopic.php?f=8&t=1452
I did it on one of my builds and it worked out fine. It disconnects everything except the battery so it can still be charged. Maybe it's not safe though, so you should ask others who have knowledge on the subject.
Lots of people seem to be using extra 'power boards', although I'm not sure why anyone uses them at all to be honest. Perhaps it just makes wiring neater.

A 'centralised' place to connect the power wires perhaps.
I suggest you research it further before deciding on what's best for your build. Like I say my knowledge is very limited and probably flawed in places, and it would be great if someone with the knowledge could post telling us more about slide switches.
