Walking lunges ok?

Is it ok to do the weighted lunges walking across the floor rather than as demonstrated in the video where you lunge forward and step back? I find I have a much slower and controlled movement when I do the lunges walking forward.

If you have the space to do the lunges as you walk, I don't think there is a problem with it. Controlling the weight and maintaining a consistent form would be the bigger issue.

They are fine until you start to push with the backward leg (feet on floor) to lift on the forward. 

while during the forward step the backward leg could assist the negative, the positive part should be a movement of the front leg. for this reason the skater squat should be previously mastered.

Thanks.  I will double check my form and make sure that I am purely pushing with the front leg.