No, if you have a bad glow plug it won't fire at all. It's rare for a glow plug to be in a state of intermittent operation, they tend to either work, or not. As long as you have the suitable temperature glow plug (hot, medium, cold) for your engine and climate, you should be fine. Always have one on hand to swap out when you have a problem, so at least you can rule it out straight away when diagnosing.
I expect your problem is related to your tuning of the engine. It sounds as though it is running very rich (rich=lots of smoke, lean=no smoke), you should adjust the high speed needle (this is normally the one sticking out of the top of the carb, the most easily accessed) in order to lean the fuel mixture. This is accomplished by turning it clockwise in very small (imagine it is a clock face) one hour increments. Each time you do this, try accelerating again, it should clean up slowly, be careful not to go too far with the needle adjustments. You want to see 'some' smoke. Too much is better than none, but a nice visible wisp of grey smoke is what we're aiming for. Also, once you've tuned it a bit and it runs reliably, don't forget the spit test, just to make sure you in the right temperature range. Spit on the engine head, if it just sits there and slowly evaporates, you are probably running a bit too rich still, wind the high speed needle in another hour and see. If the spit evaporate quickly and/or lightly sizzles, you're about right. If it sizzles violently and/or jumps straight off, you are too hot, wind the needle back out again a bit.
Hope that helps dude, that's basic engine tuning for beginners in a paragraph, I guess. lol.