What's your question? Ask

Slugs are the usual suspects when there are holes but no pests to be found. They only come out at night, so they are hard to spot. This article will help: https://www.gardeningknowhow.com/plant-problems/pests/facts-about-slugs-and-how-to-kill-garden-slugs.htm

It sounds like it may be a fungus. I would recommend treating the plant with a fungicide.

You can use an undiluted 3% solution on plants. But, always when using homemade formulas, test it on small part of the plant to make sure that it is not overly sensitive to the mixture.

A number of things could cause this, depending on the type of plant. Most likely the blooms are being cooked by the heat. Even if you water the plants, in high temps, it's more difficult for the blooms to get enough moisture in order to protect them from sun damage.

Sometimes it is just the age of the bloom, which will start to turn brown as the bloom ages and dies. It can also be caused by windy conditions that cause a bit of wind burn. Sometimes it can be caused by a fungus or insect problem, but the plants will usually show other signs of distress.

This sounds like a fungus. treat the plant with a fungicide and that should clear up the problem.

They may not be getting watered deep enough. If they are in containers, make sure to water until the water comes out the bottom. If they are in the ground, water 1-2 times a week for 20-30 minutes or until your watering system has put 2" of water onto the soil.