2) >do we really need to prioritise and help huge miners
No, we help all miners. Not only the big ones? Also, calling non-monetary transactions "spam" is a bit one sided in my opinion. Sure, you can see it as spam, but why is that spam and all other transactions unrelated to you are not? Both are to no use for you and you still store both on your own node.
3) AFAIK Luke Dashjr is the ONLY contributor to bitcoin knots and he commits without reviews. I didn't fact check this, but that would be an issue towards me. The OP_RETURN unlimited thing is less important than an introduced vulnerability that nobody is aware of.
I know that we both want the same. My concerns are anyways for things far in the future. But imho, we need economical incentives and not morales. That being said, I don't care if this OP_RETURN limits gets increased or not, but I'm still not sure how I think about this "filtering" thing. I think filters are here to stay, but I just don't see how they are effective, if they don't follow economical incentives, because miners will use the software that does. Miners want the max amount of bitcoins possible for the least amount of invested energy. Knots nodes not forwarding these transactions is useless, as the big miners anyways have direct connections with each other.
I prefer following economical incentives, as long as the network remains stable. If we see that we took the wrong path, we should fix it from there. If we see that it works, then we have created the best bitcoin possible.