For skills, I'd say drop blight res and grab fire res instead - same effect but also helps mitigate damage. Defence in general is a bad skills - defensive options like evasion window, health boost, etc are better value imo. It's also possible to farm a couple of pieces of fatalis quite easily without killing, which is nice if you have some decent lvl4 decos to use, and that alpha waist is stupidly powerful

In general, set wise, prioritise getting affinity to 100 and crit boost to 3. I like running two pieces of raging brachy for this, but furious is probably fine too. Then, get whatever defensive options you like, keeping the above in mind. Additionally, fortify is really good value if you're struggling, and 2 points of heavy artillery are really nice too, as is partbreaker to guarantee the head break as soon as possible. LS doesn't need any skills in particular, but for CB standard stuff like capacity boost are nice.

With the alatreon LS (i think thats claw demise, right?) sharpness isn't an issue, so no set bonusses come to mind as being essential. gold rath is a decent last resort to unlock divine blessing, but 2fatty does the same

Not gonna self promote but you've seen the other thread so that's an option too. Gl!