By choosing to limit your Next Actions, I think you're creating a system that you cannot fully trust -- which is ultimately the reason why GTD works.
I'd suggest prioritizing your projects instead. You can do something simple (e.g. A or B) or a bit more complex (I use a 1-5) system. Keep a separate page of Next Actions for projects in each priority -- so 5 pages total if you have 5 priorities -- and order them so you'll always see Priority 1 projects first. Then if you don't feel like doing any of those tasks, you can progressively move down in priority until you hit fixing the door.
By keeping the screw on your active @ERRANDS context list, you increase the odds that when you're out and about anyway, you'll also be in a position to quickly buy a screw, saving yourself an entire trip in the future. Or you may need a 20-minute mental break from your current project which you could spend screw shopping. Since you CAN do it right now, you may as well have it on your list.