What's your question? Ask

This will not harm you, and will be safe to be consume. It would be best to treat the problem though. You may apply wettable sulfur at any time. This will take care of the issue in the soil, and that will allow the tree to correct the issue in itself.

This could either be one of two things. Either this is an infection, or the pH of the soil has drifted. You can add, both dolomitic lime, and wettable sulfur the the area. This will correct both problems at the same time. Even if there is no infection this treatment will be good for the tree.

Yes, the seeds or pits need a 60 day period of cold stratification.

This article will help you.

https://www.gardeningknowhow.com/edible/fruits/apricots/growing-an-apricot-from-a-pit.htm

If you do not regularly fertilize this then this may be the issue. You should do this once per year. I would recommend dolomitic lime and iron sulfate incombinatino over Epsom salts. This till give calcium so that the magnesium can be taken up easily. You can add this, but this may not help with flowering. This will require potassium and phosphorus.

If they cross pollinate, you will only see the results in the next seeds fruits. So as long as you are not planting the seeds from them, then there is not a risk of the fruit being changed. You are safe to plant it near your other trees.

Yes, it would be too late to spray them with this. This should only be done during dormancy. I recommend neem oil. Just make sure to spray OUT of direct sunlight to avoid burning.