2 and 4 are Niche, the Rest don't even make sense for this video, You should've just called this "Gadget tricks you didn't know" And found more uses instead of the most obvious ones, not counting 2 and 4, which were actually good. (Even then, 4 can be done with normal shots.)
Bro thats not where surges gadget is for! You should not use it as a shield, you should attack 2 times or even 3 times, and just before getting hit by any damage press it so you get your ammo back and get a free kill
For surge: he also gets ammo, mainly use it to get kills and etc, however the tip in the video is useful. For cord: you can just use your super, you can also escape everything. If you dont have one, use the gadget. For tick: pretty good! But you should save it for mortises and edgars. For darryl: only works if their standing still, your better off trying to chip enemies so you can get super charge with the gadget.
Hi. I can't help you because I haven't played for a long time and I'm currently weak enough to appt rank 30. But I can tell you how I did it. If you play a lot, against strong opponents, you improve your skill automatically. I got to the point where I was winning on 950 trophies with randoms. You just need to try and play more, try to find a team in different social networks. Good luck!