@danj pretty much answered the question, anything struck by lightning is fried. Even though there is heat on the SOC it is probably doing nothing as all the IC's are fried by the huge jump in voltage from the lightning. For the future to protect against lightning you can install a surge protector for lightning that look like these These are for the EU, if youre in north america im not sure what the standards are there sorry.

Seems like a power button issue that is being pressed at random. It is probably the chassis (did you ever drop it) pushing up against it, by tightening the screws it probably helped a bit by relieving the pressure on the power button. Can you check to see how the power button is (and if its damaged at all).

I had this issue when I dropped my iphone also, most likely you are going to need a new screen. As @conorbone said follow this guide to find out what you should do: Remplacement de l'écran LCD et de la vitre tactile de l'iPhone 6s . I also had this issue when I swapped in a display (turned out to be faulty) and the connector was not connected properly resulting in a bad connection and similar looking lines.

Hi, looking around you have multiple options, unfortunately most of them are third party because apples self repair is a joke. I believe that the 2020 is a gen 2 iphone se so looking on amazon i found these: https://www.amazon.de/-/en/MMOBIEL-Charging-Port-Compatible-iPhone/dp/B079Z92VT9 (and yes this does include the bottom mic) https://www.amazon.de/-/en/dp/B0CRRBQLFN - unfortunately i coudnt find just the speaker, if you have other 3rd party websites try them as going through apple is not going to be realistic.

Checking with openboardview it seems to be a fuse as @zpl said. The fuse seems to be unrelated as the ssd should still work. So I would try to narrow down the issue. Do you have any other macbooks that you can swap the ssd into to atleast see if it boots? and before you start messing around with the laptop is there any important data on the ssd that you need to recover?