Yes it will work with the Switch. You just need to update your system to work with XC (Extended Capacity) Cards, which it will do on it’s own once the card is installed. Remember to turn your console off while switching SD cards
Yes it will work fine in galaxy s8 s8+ s7 s7 edge Note 8 those phones say upto 256g because that is what cards were limited to before this card. the phones listed can do up to 2 TB if cards were big enough
Yes, as long as you format the micro sd card to FAT32. Done it with a 200GB micro sd card I bought from Sandisk and now it shows 999,999 blocks available on my New Nintendo 3DS, no matter how much I put onto it. So you might want to go with something less than 200GB if you want to save money.
I can only assume the camera is digital and like most security cameras the recording features multiple speed setting especially if the camera is used in a remote area to record long periods of time. If the camera is capable of handling an SD card you shouldn't have any problems.