I think you raised a very important question and i very much agree that one should be honest with oneself what one truly cares about.
When it comes to the interventions you proposed i am nor really sure about the practicality. (2) sounds doable but i’d guess that the side effects of losing the ability to strong pain are severe and would lead to self-hurting behaviour and maybe increased fighting among the animals. But if it was possible to find a drug that could be administered to animals to reduce their suffering (maybe just in certain situations) without major side-effects, that could in fact be an effective intervention and may be worth looking into, mainly for the reason that it maybe wouldn’t come with big costs to the corporations doing the farming. It may, however, help to sustain factory farming past the point it could be abolished otherwise, which would probably cause more net suffering.
I don’t know how much time breeding animals that are radically different from ours takes and I’m generally a bit more sceptical whether it’s worth persuing that.
In general the main problem with this way of fighting animal suffering is that most people concerened about animals wouldn’t support it and they probably also would have no problem admitting that they care about more than just reducing suffering. I think that it’s probably better to persue strategies for animal suffering reduction that most people in the movement could get behind.
So i think their could be some value of researching this approach but I am sceptical overall.
I think even if we believe that plant-based and clean meat as well as change in attitudes can get us to a world free of, at least, factory farming, it may be worth looking into the strategies as plans for what we might call worst case scenarios, like it it turns out that clean meat will remain too expensive, plant-based alternatives fail to catch on and a signicicant part of the population fails to be convinced by the ethical arguments.
I also think that those ideas may be more important in countries that are only just building factory farms compared to western countries.