I would be interested in both glider and tug pilots stories of things that commonly go wrong, and how they are dealt with, if anyone is happy to relate?
I've been towed behind a tug which would not climb, made more interesting in that we headed away from the airfield in a straight line for an alarmingly long time. Later that day I saw the same tug (still not climbing) veer off the runway line immediately after takeoff and only just clear a combine harvester. The glider pilot told me his intention was to pull up as the crash happened and thermal away from the resulting conflagration.
But generally the only complaint glider pilots ever have about tuggies is they are towed to dead areas of the sky, rather than the booming bit they wanted.
From the tug end, the big worry is the glider getting high and stalling the tug - this can be fatal. Glider airbrakes popping open on tow is alarming because you can barely climb, but the approved technique is to drag the idiot to height (I confess, I've been that idiot once, though only for a few seconds) and then leave him or her to work out why the ground is approaching so rapidly - this one is tedious but generally not unsafe.
Tug pilots get used to gliders being in strange positions - during my Basic Instructor training I was made to formate on the tug's wingtip while still attached and then return to the normal tow position. A bit of a jerk on the rope that time, but experienced tuggies seem not to notice their tails being pulled round the sky.
I suspect that much of what a tug pilot experiences would seem quite alarming to a normal PPL
I think Mary towed me a few years ago when I was visiting Shenington (Super Cub?), but I doubt she recalls the experience because I flew fairly well that day.