Usually, as the vegetable grows, the bloom dies and falls off. Any idea why this is happening?
Sometimes this can happen, where they will remain for longer than needed. It will eventually fall off before the fruit is ripe, and if it doesn't for some reason, then you can fry these flowers and eat them too!
MY ZUCCHINI IS ABOUT 3 FEET TALL, NOT PRODUCING ANY AT ALL
Zucchini are generally a sprawling plant.
A 3 ft tall plants sounds very unusual.
Lack of flowers or fruit could be due to soil nutrient issues, weather extremes or lack of pollination.
On zucchini
These articles have some good information:
https://www.gardeningknowhow.com/plant-problems/pests/insects/squash-bug-control.htm
White pimples on zucchini fruit - is it safe to eat?
This is bacterial in nature, and only affects the fruits look and production quality. It will not harm you to consume these, and will be safe to do so, but I would recommend finding a new location in the future. Plant some other things in this location for a few years to make an attempt at soil remediation. High oil plants, such as thyme, basil, or anything that has quite a bit of smell can help. Garlic and onions can help as well.
My zucchini plant has very large leaves that covered the plant and the zucchinis that started to grow. There are white spots on the stalks near the base and the zucchinis that were there turned mushy and dying.
This sounds a lot like a downy mildew infection. This article will outline what can be done to correct the issue: https://www.gardeningknowhow.com/plant-problems/disease/cucurbit-downy-mildew-control.htm
My garden was sprayed with grazon about a year ago. Nothing came up this spring except zucchini. Is it safe to eat the zucchini?
My guess would be yes, its safe to eat the zucchini, but I'm really not familiar with this systemic herbicide or the residual toxicity issues.
Here is a link to the Canada office of Dow AgroSciences. You can ask your question directly to the product manufacturers rep. If you are in the US or elsewhere you may find a similar contact page. The other option is to ask your state or province pesticide regulation department or county agricultural commissioner.
My zucchini is getting very crowded, will I have better results if I cut some of the bigger leaves or will it hurt the plant
Typically, you will not want to trim living leaves. This leaves the plant very susceptible to disease.
It is best to plant them with how big they get in mind. They will naturally spread into a large mound or short vine, leaving themselves ample room between leaves as long as they are planted in an open area.
They are better off crowding than cutting, but if the leaves start dying off then you can cut them once they do.
This article will help you to grow zucchini: https://www.gardeningknowhow.com/edible/vegetables/zucchini/growing-zucchini.htm