First off, I don't think you suck nor does your videos, to each their own, I did notice that the Like/dislike ratio wasn't great on your videos but you have remember that this is not necessarily a reflection of your skill (in game or video editing wise), but I think if someone stumbles across your DH video for instance who is not a DH they might not see the same entertainment value in you using some of these "broken" abilities and mechanics
. So I don't think you should let stuff like that discourage you.
Your video editing skills will grow with time, as long as you push yourself, try doing something new (however small) in every video, it might be a silly transition between cuts or a more colourful way for the text you display to appear, but once you've done that you know how to do it and you can use it in future videos with much greater ease. For a good short video essay on this I would recommend "SovietWomble - The Art of Subtitles". I'll try to give an example, in the video where the Warlock is channelling is Chaos Bolt you show down time (great stuff), maybe try slowing it down even further, do a cut away gag to maybe Dragonball Z of one of the characters charging up an attack, keep the sound from Dragonball rolling while you cut back to the ingame footage in super slo-mo and then when you chain behind him at the last second put in like a very brief fart sound (or someone blowing a quick raspberry if you know that term
) or something else signifying that it fizzled.
In terms of your in game skill, I would personally recommend trying out Arena, setting yourself up against players of equal (or greater) skill is really one of the best ways to learn and hey, if you do recordings of it all it's actually easier for you to go back and look at your mistakes and failure is pretty darn great teacher.