Is a flat swing a bad thing?

[One Planer]

Your swing position at the top very much resembles that of stack and tilt whereby your head is over the ball and your weight looks like it favours the left side (not posted over your right leg at all), perhaps you might consider looking into it as it'll show you what to do on the way down and hit nice 'draws' all day long.

I did look into S&T a while back (not longer after I took the game up). The principal seems good, but I couldn't master the practical side .

You're quite right I do hold slightly more weight on the front foot. My game used to suffer from hitting 90% of my iron/wedge shots fat, probably due to the fact I was swaying off the ball. Since re-balancing my weight I find I'm getting better contacts as I'm hitting against my left hand side.