If your hing lines have any gap, use some electric plane hinge tape and seal the gap up. Just make sure you still have movement. Air thought a gap will cause the surfaces to flutter. I didn't see any evidence of that in the video, but it is a good thing to eliminate before it can cause problems.

What I saw on the landing approach was a plane that was about ready to stall. It didn't have enough air speed to answer the controls well. It is best to keep up some air speed until you are just off the runwan then cut power.

On a windy day you have to keep in mind that your mind gages speed in relation to the ground, not air speed. The plane needs air speed to keep flying. IF you are flying up wind, your air speed should be above above stall speed if the ground speed looks OK. On the other hand on a down wind leg, your air speed may be near the stall point with the same ground speed. Also remember that the inetera of the plane is related to ground speed. If you are on a down wind leg, and your air speed is near the stall point, turning up wind will give you more air speed for a bit. The reverse is also true, If you are flying cross wind or up wind at near stall speed and turn down wind, you wind speed dropps off to the point you will stall. I lost my 4 * 60 like this a couple months back. You need to keep your air speed up above stall speed until you are inches off the ground on a landing. The first indication on most planes of a near stall is that the controlls go mussy and you get the all over the place approach as shown in your video. The plane is slow to respond to the controls until you have over controled then it jumps to that control which is to much. You correct and in turn over correct and the plane has a very unstable approach. Just a little more speed will smooth this out.

Don