First, at 50 degrees you shouldn't need glow plugs to start. But this "cycling" thing... You know the WTS light is No indication of GP function, so no need of the cycle. Turn the key to ON, and leave it there and the plugs will be on for as long as needed (up to 2mins in Real Cold). If you've been plugging it in all Winter, your GP system isn't much needed either.
Check it out here -> Troubleshooting GPR & GP's
Next, Anytime you get a WIF indicator you should collect the discharge and look at it to confirm you actually have Water (Look above the pass ft tire, you'll see a 3/8" metal tube, against the motor that ends there, it's the drain for the bowl (yellow lever you slide to the side). Get a cup, open the lever, drain the fuel bowl)
Finally, YES the "1/4 tank" is a significant place for running dry. The pick-up, in the tank, has been know to crack or even fall off and limit you from going any farther down. I would start here. Go pour at least
5gal in the tank (10 is better) and see if this solves your problem...
The white "smoke" you see is Fuel so, it's likely you're getting that to the injectors. Have you seen an SES light at all?