From what i have heard, you should never put electronics on the outside of an esd-bag, as it doesnt have the same properties as the inside

Well yeah a ESD bag does not do its job of protecting electronics if they are just placed on top of it, but its not any worse than placing it on any other random surface such as a wood table or something. If you have a proper grounded ESD work surface then yeah use that, but if you don't then placing your boards on ESD bags is completely fine too.

What you do have to avoid is powering up any electronics if they are sitting on the black ESD foam material. That stuff is indeed rather conductive to the touch and could make a powered on board act up (And is even dangerous if its running directly from the wall)

That last part is what i was going for, the shorting out part

No need to worry about it so much. I design electronics like this for a living and they are not as delicate as people often think.

Okay a metal spudger is a bit rough but the plastic ones don't last long if you use them often. If you start it off with your fingernails and then just use a metal spudger to continue along the already open seam you can get away with no damage at all when done right. Also depends on the design of the case, some have a dedicated spot where you can easily get it started.

Placing boards down on non ESD safe surfaces is completely fine, as is touching all of the board with your fingers without wearing an antistatic wristband.(Just don't use a PVC table and rub your hands vigorously over it before touching the board). You do want to avoid touching any exposed contacts (Such as seen on RAM sticks) because the oils and sweat from your fingers could corrode them. Don't wear static generating clothing while working on electronics. If you do something that might generate static (Like taking off your shirt) then just grab something grounded for a moment before continuing to work on it. For the usual electronics you need a static discharge strong enough to feel it as a shock before it can actually fry something (Tho it might survive even that). No need to store electronics in ESD bags, but it is a good idea to do so if the electronics are to be moved around a lot(Especialy shipped trough mail) or handled by people who do not know about good ESD practices. There are some specialised high speed and RF electronic components or diode lasers that are indeed incredibly sensitive to static and need to be handled with ESD precautions, but such devices usually cost 10 or even 100 times what your whole monitor cost,, not normal consumer electronics by far.

As for the screw falling on the PSU board, yeah that's not the best but normally the capacitors in these things discharge within 10 seconds of being unplugged and even plugged in there are only a few places on the board where a short circuit would actually cause damage. They tend to become more dangerous when the PSU is broken in some way and this can sometimes cause some capacitors to hold charge much longer than normal, so its best to assume a PSU is unsafe until you actually measure it with a multimeter to make sure the main capacitors are empty.

Much like how people think that touching electricity can instantly kill you. I have lost count how many times i got shocked by 220V mains, sometimes its a bit of a tingle, sometimes it really hurts but as long as you follow a few rules its not really gonna kill you, its just unpleasant. Its more of a scary boogyman that you can't see, but since the general public does not know what cases do make it deadly its best to just assume any electric shock can be deadly. Similar thing with ESD precautions.

Thumbs up for you.

Though I do have to say mostly the worries were also that the guy acted like " I fixed other models but this model , my first time " as he looked very clumsy. Also you're probably right about caps since monitors don't draw THAT much of power. (* Different story i think, for actual computer PSUs that actually is rated for few hundred watts, I have 850W 80+ Platinum PSU and i have to discharge the PSU by pressing power button after unplugging, else it feeds motherboard for like 20 seconds )

Well sometimes things are put together in a way that is pretty clumsy and annoying to work on, especially some badly designed laptops, or sometimes you just need to know the exact procedure for disassembling that specific model. But yeah sometimes people are just clumsy themselves, still better than having someone do it who has never opened a monitor before.

And yes its quite common for computer PSUs to run for a good bit of time time when the computer is in standby because its taking very little power from the capacitors. But electronics still draw a bit of power even in standby so that does slowly use up the charge in the capacitors. The danger is when the PSU itself is broken so it is not transferring the power from the main input capacitors on to the rest of the circuitry. In such a case there is nothing taking power back out of the capacitors so they stay charged for hours or even days.

I think people shouldn't be afraid of fixing there own stuff themselves, most repair technicians are not really all that smart or have some superhuman capabilities. Its just a matter of taking the thing apart, replacing the broken part and putting it back together. People that know how to build there own PC can just as well fix a washing machine given they can find the information how to fix it and get the replacement part. Its the low level board repair like fixing a laptop broken motherboard that needs skill, knowledge and the tools to do it, just replacing it doesn't.