Guy, If you don't see it as bad it is due to my inability to communicate what is happening through the written word. This takes the stick out of line, creates a very imprecise cue ball/tip contact point, just a mess. I thought this was the best way to apply spin and I just had to learn to control it. After months of intense effort all those years ago it lurks to screw up a shot if I get my hand too far back.
Other habits included extreme spread between my bridge and back hand. Unsure about inherent evil in this practice but speed control with modern cloth and cushions is a lot easier if I bring my grip hand forward. I even move the grip hand far forward and do what I call bunting the cue ball to good effect on the short track, seven foot tables. I haven't tried gloves or other mechanical means other than proper practice to break my bad habits.
Butting into the snooker stance conversation, the big deal in my opinion is more anchor points. In pool we often have the bridge as the only fixed anchor point and the grip as a floating anchor point. The snooker stance may add the chin, the chest, up to three fixed and a floating anchor point. If we picture a rod or pipe moving back and forth through a space with only one fixed contact point and another with three contact points along the length of the object and at various places around it, it should be obvious that the range of nonlinear motion is vastly more constrained with more anchor points. Also when we bring all of these contact points to the cue, our bodies have to be in a very consistent position over and over.
Something an explanation of would benefit hugely from diagrams and pictures but in general pool and pool players are much more free form than snooker and snooker players. I practiced for several years on a snooker table with a pool cue. The goal wasn't to restrict my pool game with all of the anchor points of snooker but to make my more free form style more precise. I suppose it would be similar to someone using a batting cage or a tennis ball cannon to groove in their swings. I don't know if this is true. I am uncertain if I ever tried a batting cage and I certainly never tried any formal tennis training.
Snooker stance forces you into a very repeatable position. Pool can be much more free flowing. I think free flowing is more enjoyable, probably much less chance of error with the precisely repeated platform. No question where I fall, I still practice the slipstroke simply because done right it is an art form.
Hu