I think the most common misconception regarding thrush is the horse needs to be wading in mud 24/7 to get it. Nothing could be further from the truth.
The frogs pump blood therefore there is heat/moisture in there. Heat/moisture attract fungus/bacteria from the ground, regardless of how rock hard & dry that ground is.
I also think it's the first picture that the frog is growing crooked. The picture isn't skewed, the tip of the frog is pointing at the ten o'clock position
Healthy and properly growing frogs should always point to high noon
If the horse toes in, that might be one reason. Poor trimming and the horse is off balance could be another. Something unhealthy going on inside the hoof might another. All that thrush may be the cause.
I hope the farrier can answer the question
Regarding sole & frog shedding. That can depend on the climate and the horse's living environment. Horses that are stalled more than they are out may shed at a different rate. My four are on a lot of acreage, they did their normal Spring shedding.
They shed again after a few months of Severe drought ended and the rains came. We went from threadbare pasture to not being able to keep up with the bushhogging in only 10 ten days. The heat/humidity also shot up. All that drastic weather change caused them to shed again.
They will still shed frogs & soles one more time, later this fall.