I would not be aiming for the threshold like you did in some of these clips. If you have no power at least aim for the thousand footers. That way you have 1000 foot margin of error if you are short. Also, as a glider pilot that pattern looks huge to me. Glider pilots fly a much tighter pattern. That way if we are getting low the field is right there. I would be turning base much earlier in a power off situation. I would be keeping it high and then once you know you have the field made add in slip to get down. You also mention that you are having problems maintaining the correct speed. I would guess you are aiming for a spot on the runway and then based on how it is looking you are either pushing the nose over to try to get down or holding the nose up to try to make it to your intended landing point. That is not going to work. You need to set the trim and maintain your pattern speed the whole time and use slip to control your descent rate. If you are high add more slip, if you are low use less slip. With gliders we have spoilers to control descent rate. So throughout the entire pattern we are maintaining one speed with the stick in our right hand and then adjusting descent rate with the left hand.
