Comments in order:

First of all, a general remark: Less Wrong Is Not Lifehacker. I would prefer LW not to become dominated by, so to speak, mundane self-help. Not because there's anything wrong with mundane self-help (quite the contrary, I think it's an excellent thing) but because there is lots of it out there already and I think material of that sort belongs on LW only if there's something genuinely new/different about it in an LW-relevant way. For instance, a strong empirical focus with actual evidence that the thing works; or (maaaybe) advice that's specifically relevant to exceptionally intelligent compumatsci types with akrasia issues. (I'm not convinced the last of those should be enough on its own.)

In what follows, "LWINL" is short for a re-recitation of the foregoing paragraph. (In particular, it doesn't mean "this definitely doesn't belong here", but something more like "this doesn't belong here unless there are special reasons why it does that aren't yet apparent to me".)

(I have a vague feeling that we once had open threads with a self-help-y theme. I forget whether we still do. That might be a good place for some things that aren't so exceptionally good or LWish to merit posting as articles but that are still a notch more LW-appropriate than your typical Lifehacker article.)

One other general remark: My feeling is that most of these things would be better handled as blog post + link in open thread than as LW posts.

• Goals of LW group: not interesting to me, might be useful to others, would be more interesting if accompanied by nonobvious information about what goal-deciding processes empirically work well and what ones don't.
• Goal interrogation/levels: might be interesting with good empirical evidence; otherwise LWINL.
• How to human: probably not; LWINL.
• Getting-shit-done strategies: LWINL.
• Superpowers and kryptonites: LWINL. Also, might be worth thinking of in two parts: (1) an exhortation to be explicitly aware of one's unusual strengths and weaknesses, and (2) a listing of likely strengths and weaknesses.
• Effective behaviours: LWINL.
• Stress prevention: LWINL.
• Make it easier for future you: this does seem to have a somewhat LW-specific flavour, with hints of TDT/UDT about it. Is it a thing that's clarified by looking at it through LWish decision-theoretic eyes?
• P=NP approach to learning: Interesting iff it comes with genuinely compelling examples and a plausible way to apply it.
• Guide to dating: my first reaction is "oh god please no" but maybe that's unfair if there is genuinely rationalist-specific advice in it.
• Training inherent powers: interesting almost exactly in so far as it contains empirical evidence and actionable advice.
• Steelman not strawman: could be good; you should check for overlap with already-posted stuff on LW, SSC, etc. "More poetic than anything else" worries me a bit.
• How to approach a new problem: probably useful iff it has solid empirical evidence and good examples.
• Stimming: no, this is not the sort of content LW is for.
• Time management: LWINL.
• Spices: sounds interesting but highly non-LW-relevant.
• Winging it versus planning: LWINL.
• On-stage bias: it's not clear how far the word "bias" is actually descriptive as opposed to being a rationalization for posting generic self-help advice on LW. LW-appropriateness is more or less proportional to how far it is :-).
• Creating a workspace: LWINL.
• Cost/benefit analysis: LWINL, but this feels slightly more LWish than most.
• Extinction learning: might be interesting, but hard to tell until the idea is more fully formed.
• Dating ad: oh god please no no no.
• Aversions: probably not but again might be easier to tell when idea is less inchoate.
• Lists: LWINL.
• Remembering details: interesting psychologically if the central claim (that you can actually choose to remember names) is true; how does this generalize?
• What is a problem?: no, make it an introductory part of something more substantial if it turns out to be needed.
• How to attend a meetup: not interesting to me but might be to others. I have a vague feeling someone already posted something along these lines, a few years ago, but my memory is super-unreliable.
• Noticing the world: I don't understand what the actual topic would be.
• Least-good but only solution: maaaybe. Do you have a few good examples? Is there a bigger picture? (I'm thinking e.g. of Eliezer's post about "the lens that sees its flaws".)
• Self-management thoughts: again not clear what you'd actually be saying; hard to tell until the idea is better formed.
• Subgroups: probably not appropriate for LW.
• If nothing to do, make better tools: Totally uninteresting (to me) as a "poetic style motivation post". Might be interesting if some actual empirical content -- examples and evidence.
• What other people are good at as support: does't sound appropriate for LW.
• Focusing: sounds like it might be LW-appropriate.
• Rewrite of !2000-year-old vampire": might be worth it.
• Tell people your goals?: maybe.