What's your question? Ask

These are NOT silly questions. They are very important to know.

They are likely at the end of their run and the heat is likely the cause. You can go ahead and pull them and plant other vegetables that will grow now. You can replant peas and beans when the weather starts to cool down again. Many gardeners get 2 crops with peas and beans, one in the late winter/early spring and one in the fall/ early winter - depending on where you will.

Here is more information on peas, if you are interested:
https://www.gardeningknowhow.com/edible/vegetables/peas/how-grow-peas.htm

You don't have to, but you will get a better crop if you do. The peas will grow taller and the pods will not be as exposed to pest and water damage.

It sounds like you may have powdery mildew. This article will help you:
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm

Try neem oil. Very effective and not harmful to people or animals. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm

Peas can turn yellow for a number of reasons. Some possibilities include too little water, nitrogen burn from the manure (though you would have seen that sooner, I think), root rot and high temps.

As long as the containers are draining well, I would try increasing water to the plants - this will help if it if it is too little water or high temps.

Peas are a cool weather plant. They do not do well in high heat and will die prematurely in that kind of heat. I would recommend looking at growing peas in the fall or even winter in your area.

As long as you get unfiltered light through that window (as in there are no trees or buildings in the way, they should grow in that window.