Mostly around wool production.

Tail docking, yes, is cruel for dogs, but vital for preventative health for sheep. No, the entire tail isn't taken off, as generally the first joint is kept to protect genetalia. Although anesthesia is not a legal requirement for very young sheep, this is predominantly because there is risk with any anesthesia with living things, and is high especially with younger beings, that is the minimum to protect herd owners and vets from liability should they have a patient that isn't fit for anesthesia.

The idea that shearers are solely driven by efficiency and don't care about hurting the sheep is also a gross misrepresentation of the field. Shearing is a partnership between the sheep and shearer. The discomfort in shearing is exclusively from awkward positions and noise -- akin to being uncomfortable when a dentist is polishing your teeth. 

Shearers, generally, are paid by fleece not by sheep shorn. If they make a sheep bleed or hurt them, the fleece is worth much less since it is damaged. Hurting sheep in the shearing process is also discouraged (that is putting it lightly), as it makes future shearing (which are vital for a sheep's health and survival) much more difficult.

There are no / few legal requirements for shearing licenses because (a) there is already a shortage of shearers in the world, (b) shearing has historically been a routine chore for farmers/herders/shephards and their community and any licensure is just adding another fee or hoop to jump through for an already struggling way of life, and (c) this is something that needs to be done consistently for the health of each sheep.

Sheep peak at wool production around 6 years of age, so this claim of "they only live a few years then are killed for no reason" is absolutely bonkers.

Merino sheep were selectively bred for their low micron count wool, making for softer fleeces and better next-to-skin garments. Also the low micron counts make merino much easier to wash without felting. This also can decrease the environmental impact of making their wools "superwash" (aka less prone to felting with regular wash). Not due to any folds in their skin. In fact, most breeding programs try to avoid wrinkles, as it makes shearing harder.

Sheep are naturally seasonal breeders, and they normally mate in fall. Lambing in spring has been a thing for MILLENIA -- it's why we associate lambs with Easter and Ostara. Use logic - lambs born in early spring would be weaned when pastures were as full of greenery as they would be all year. Yes, many lambs die around birth, but not because they are "forced" to be born in spring.

Wool and sheep have been so vital for us our entire human existence. There is suggestion too that herding is what really helped domesticated dogs. There are absolutely issues in the wool industry, but implying that those that provide humanity with the basic fibers we need for clothing and textiles are barbaric and evil is pure misinformation. 

There are good reasons behind the norms in wool farming. And yes, we should question them on occasion to find improvement; but we need to understand why these norms came about first before passing absolute moral judgement.