I will assume you did not read my other comment and not comment about the fact that you cannot refute a single argument made by me on this forum to this day.
Anyway, now I am going to give credits to the original creators of all these concepts.
1) Skin changer - extremely simple, there are way better ones made by other plays, ditzy-custom comes to mind but I think Civil Lite has a similar thing as most mapmakers do but this is really simple compared to these.
2, 3) Message/zoom to specific player - Mrnat, even has a forum tutorial on it, unsure if he was the first to do that but it is also quite intuitive
viewtopic.php?f=126&t=205924) Teleport gun - this is so old I have no idea of who did it, in the secret areas of my phsc-base2 there is one, very likely made in like late 2014 if the trigger actions were already in the game or somewhere in 2015, one of the first things I did when they came out, also really simple.
5) Boost gun - literally a single trigger action
6) Nuclear missile - Literally silent phoenix-missile but it is made in 2018 instead of... 2014? 15? I don't know when he made it.
7) Door - You don't give argumetns for why they should be used in approved maps, they are not synced so if one player joins right after another opened it the door is closed for the new joined player etc, and it is also extremely common but I think it was first used in some map by Eric or something.
8 ) Controllate turret - Literally eric gurt-turrets but it is slighty changed so the turrents are on do nothing and they use a region that moves to your cursor as target and then fire in specific scenarios.
9) Explosive turret - Literally eric gurt-turrents but it explodes when they die! yikes!
11, 12, 13) Elevators - How many times has this been done before.
14) PM thing - I think Max Teabag has a video or a tutorial on this but I think he was the first to use it too, anyway I might be wrong then this is in theory original as in the form of a tutorial yet not as a concept, also quite simple.
15) Revive thing - yikes! a single trigger using the concept used above to detect the chat!
16) HP check - Really simple and should be more common, I did not look on how you made it but there are many methods all simple, can be done via checking HP(then I think stryde gets the name for being the first at it because I remember a long time ago he made some SP map that I did some weird things with related to HP and then he added a anti-cheat system that verifies the players HP) and if it is slot no idea but like for sure earlier than idk 2012 or something.
17) Password system - This has been done before, with and without vars for sure, maybe names do not come to my mind, but as a visual thing that is quite fancy, while it is different, the number submitting on giraray-riddle1 and further maps, which not only are more complex and in my opinion cooler, but are also in theory do the same thing but I do not remember if he uses vars, very likely does, still the visuals are kinda creative even though it is clear that it was based out of real-life panels and I get a calculator vibe from it.
18) Explosion on player - I think that one of these 300 tutorials that kill players who say something do it, but it is also really simple and uses same concepts.
19) Sign - Mrnat made it, at least you credited him, not sure if he made it open source at some point but even then it is not really complex like many of his other trigger systems.
20) Mounted minigun - Eric made it on eric gurt-spider_traps, Mrnat has also used it twice in his maps the WW1 one and the fancy as deliciously exquisite pizza sauce sky one I forgot the name of.
21) Day/night cycle - I was almost sure Darkstar made one public as a test map, or Mrnat or someone like them, but I do not remember, it can be in Darkstar's google drive or something, but even then it was also done many times.
So well, all comments on creativity are in my opinion invalid, also most of these are forum tutorials or open sourced maps, I do not see much use in this other than the possible ones I mentioned in my previous comment which I do not think should make it a tutorial yet a single player map, but I guess you can keep talking to your friends and making so they comment here so you get publicity that gets rates and then create more "tutorial" maps instead of putting it all into a big thing for easy LDR, receiving some kind of pseudo-praise to feed your gigantic narcissistic ego in a flash game, but not a problem I guess, the day you can make something that is actually complex, useful and new is the day I will respect you as a map maker.