Very good answers.This will probably open up another whole can of worms, but, I thought I’d at least address the 5 points that you brought up.
This is not representative of CSL Wing Chun. I do not study their system, I am only speaking from my own lineage and experience.
Alan please feel free to clarify and add insight to any of the points that I address if they do not match your philosophy, I do not wish to speak for you or your system.
The 5 Points of Argument:
1. assuming a wide stance with the body leaned forward and the chin tucked down and the hands up in front of the face generally leaving the center open
2. using bobbing and weaving and generally "bouncy" footwork
3. throwing wide punches while leaning the upper body to the side
4. moving into the opponent with the head down essentially driving forward with the forehead while hiding behind boxing gloves
5. executing a punch to the abdomen by lunging in while leaning forward at the waist
My answers:
1. In Chen Qiao Quan (Sinking Bridges Fist) there is a Xun Qiao Bu (Seeking Bridge Stance) that utilizes Li Qiao (Double Bridges) in the pattern of Hei Hu Chu Lin (Black Tiger Emerges from the Forest). This is essentially a variation of Wen Shou (Asking Hands). Wen Shou has 3 positions High, Middle & Low it is a variation of the Middle position. It is a good basic fighting stance that lends itself nicely to the concept of Gai (Covering) from a distance.
2. In Biao Zhi Quan (Darting Fingers Fist) there is a method called Jiu Shen (Saving Body). Jiu Shen utilizes Wan Yao (Bending Waist) and can be applied in various permutations and if the circling is shortened up will resemble Bobbing & Weaving based upon the stance used. It is used in much the same manner as Boxing, hence the name Saving Body. Footwork varies immensely from lineage to lineage, but I see the concept of San Jiao Ma (Triangle Horse) being utilized as it would appear under heavy pressure. San Jiao Ma is usually in play before Zi Wu Bu (Meridian Stepping) & Juan Bu (Circle Stepping) are employed as it is a good counter method that maintains a bit of offensive pressure.
3. In Biao Zhi Quan (Darting Fingers Fist) there are several techniques that employ this maneuver. Gai Zhou (Covering Elbow) and Gou Lan Chui (Hooked Barring Cut) are 2 techniques that go hand in hand. Gou Lan Chui can be an elongated hook or a short hook. It lends itself nicely to Gai Zhou when in a defensive recovery mode or counter attack when the opponent comes crashing in. It is also a versatile technique that can hit from a variety of angles. It is best employed from Pian Shen (Side Body). There are more examples within the form but I think these 2 cover it. Chou Chui (Bouncing Cut) from Chen Qiao Quan also can be applied in this manner, albeit from the bottom up. It will resemble a Slice Punch, Bolo Punch or Uppercut from Boxing depending on the angle.
4. This concept can be found in my Shier Sanshi (12 Loose Techniques) it is known as Huan Hun Yao Tie Ban Qiao (Emergency Waist Bend & Iron Half Bridge). It relies heavily on the concept of Bi Ma (Pressing Horse) and is used as a method of covering under heavy pressure. It can be employed as defense for countering or offensively to break the opponents structure. It lends itself nicely to Throwing & Grappling.
5. In my line we call this punch She Shou Chui (Snake Hand Cut) it uses the principles of Sui (Follow) & Lou (Leak). It’s use depends on the position of the bridge and if the bridge is an obstacle. It is employed in the same manner as on the video when coming out of the Huan Hun Yao Tie Ban Qiao position. It is very similar to a Body Jab in Boxing when thrown from a distance, in close it will resemble "typical" Wing Chun.
Now you may not be familiar with my terminology, there is nothing I can do about that, it is what it is. I think I’ve satisfied the requirements of the questions posed, but I’m sure you will re-butte my answers as you always do and counter with more questions. You might also want to take a moment to reflect, as there is a very prominent theory out there that Wing Chun was developed in response to European Boxing methods that were used by the British Sailors during and after the Boxer Rebellion.