I use the same equipment and not had a problem with carry over smells or stains. I give everything a good soak with Oxyclean Free after every use so my plastic is very pristine. For long time bulk aging of wine (after fermentation), a glass carboy is pretty important. For initial fermentation, a bucket is fine.
The instruction with the wine kits I've used have been very good. Some wine kits are made to be consumed early and some require longer aging. For the most part I keep the the instructions exactly with the exception of some of the timing. After the first racking and particularly after stabilizing, I usual leave it longer than the instructions say as there is no need to rush to bottle. Wine making is a perfect hobby for the procrastinator.