[@Fallenreaper]
1. Gonad's strength isn't really quantifiable. He's as strong as an unarmed man needs to be to fight on even ground with similarly skilled armed and armored opponents. Generally though, his blows can kill normal humans if delivered to the head and can put superhumans out of commission. He is stronger than any character that uses a weapon, as a point of fairness given his very low durability and combat range. Same case with speed. That doesn't mean he's too fast to hit or too strong to beat. It just means that he is a power oriented martial artist capable of fighting with knights and Vikings and shit. 

2. Gonad's build is unusually dense and broad as well as tall, and his body\arm length proportions are scaled up from the reach of MMA fighter Jon Jones, so he has excellent reach for his height. Still far less than anybody with a sword, which is one of his biggest weaknesses.

3. He did not step forwards, it was not necessary. I made no mention of him doing that, and he did exactly as I said he did. Naturally he went through the motions required to launch a back kick, but I don't waste time going on about all of the confusing body mechanics. All those silly descriptions of pivots and multiple joints and diagonal clockwises are entirely moot imo. A straight punch is a straight punch, a roundhouse is a roundhouse, a spinning back kick is a spinning back kick. If I plan to do some wacky stiff-body kick that involves unlikely physics, I'll make a mention of it. Otherwise, it is just what the tin says. Trixi is however close she moved to Gonad in the first place, I never had him move after he stopped to prepare the punch. I'd assume they are pretty close together, and that's as much an answer as you can expect to get from me. I write like I'm telling a story, and as you have likely guessed I do not deal in specifics. Feel free to interpret things how you want, but when I describe something, I mean exactly what I describe. If you say she is close enough to kick Gonad in the back of the knee, then I'll take your word for it. Doesn't mean it will work, but I'll assume your character has been the physical requirements to attempt such a thing. The following image neatly sums up my roleplay style.
[img]https://embracingthepositive.files.wordpress.com/2014/11/popeye_iyamwhatiyam.jpg  [/img]

Whether or not she is moving, Gonad has great aim and is intending to give her the goods based upon wherever the heck she is. And like I described, Gonad is expecting Trixi to expect a counter attack, hence the fake backfist. There is something to be said for when one anticipates and plans for a move only to encounter something entirely different. When someone throws a surprise attack at you, you don't see it coming in slow motion. At any rate, if things are still confusing, here is a little video with a kick similar to Gonad's. Notice how flexible and normal the stance is and how the kick still has obvious power even with Uriah not going through the full motions.
[youtube]https://www.youtube.com/watch?feature=player_detailpage&v=hN-eOPFYuyE#t=21[/youtube]