I'm a little confused about the purpose of this post, and maybe this is why it's had a couple of downvotes and hardly any comments. It seems you're presenting some research questions of interest to you, but in topic areas you haven't been able to explore in much depth. I think you've done yourself a disservice by presenting them as a big, unrelated list without explanation or justification, and even more so by admitting these are casual interests of yours not worth much of your own time. Several topics on your list have generated interesting discussion on LW in the past, but the style of the OP doesn't really leave room for others to engage.
I also wondered about the way you framed the post overall. If you wait until 7 years post-PhD to begin pursuing topics of your choice, you may find it extremely difficult to attain "an academic rank of some standing", or having done so, to secure funding for a project in an area in which you have no track record. It's also not clear from your post: do you intend to do a PhD (and subsequent research) on topics that do not interest you? This too seems potentially problematic: getting a PhD can be a major challenge even for students who have an all-consuming interest in their topic.
A more typical trajectory (at least in my experience, in cognitive psychology and allied disciplines) is to start building collaborations and doing work in areas of interest at least in the later stages of the PhD, and definitely in a first postdoctoral position. Or, traditional academia is not the only avenue to pursue interesting research: private sector research is not to be sneered at.
For various reasons, they are either too removed from what I can find on the internet to satisfy my curiosity then and there, or there is too much content in the fields to dedicate enough time to it without risking time spent on other things that are important to me.
Quite often those question make good question for StackExchange. In particular http://cogsci.stackexchange.com/
I'm not too familiar with research gate, but for the rest:
Quora: By far the worst when it comes to objective facts. While there are gems here and there, most upvoted answers read like pep talks, and usually don't have much content beyond that of a decent pep talk. Go here if you want a pep talk or a popularization of some scientific concept.
Stackexchange: is where you want to be most of the time. The answers are good, and their accuracy is much better than anywhere else on the net. If you're asking about a topic anywhere close to mainstream in academia (or if you're interested in computers), you'll find an expert on that very topic.
Lesswrong: Honestly, lesswrong is too small. Unless you're going to ask about niche topics (EA, Singularity, Cryonics, and the like), there's a good chance nobody here is an expert on what you're interested in. If you are interested in the niche topics, you'll find people willing to give you detailed answers. But beware of only getting one side of the story. The answers you'll get don't necessarily reflect expert consensus, or even rationalist consensus (See yvain's opinion polls and how they match up with the comments you read. Also, check out all the other rationalist hubs. For instance, the tumblr rationalists have a markedly different atmosphere.).
Discussions are are different medium than the straight "question and answer"-format. LW leads itself to discussions.
StackExchange has the advantage of having quality standards for questions. I think it's often the best place if you clearly know what you want to know.
I use Quora only when questions are off-topic on stackexchange.
I'm not familiar with Research Gate Q&A.
Stackexchange: Highly preferred among the four choices listed. Works especially well where there is a clearly constrained question that could actually be answered in a constructive way. Several of the research questions in the original post might get constructive answers if posed there.
Lesswrong: Good for open-ended discussion, of a highly critical nature - community standards expect a certain level of rigour.
Quora: I've never used it so I don't have any comments there.
Researchgate: I have a research profile with my CV on it, and all the publications I am allowed to distribute. But I find that the Q&A section in my field is mainly something like "I need a specific kind of resource, can anyone help me find it?", and often answered in uninformative or useless ways (e.g. "here is a vaguely related paper, go read it and see"), by people who just seem to like answering questions (cf Yahoo answers and all of its ilk). Very handy for keeping up with new publications (not paywalled) from people whose research I follow.
This thread originally contained a list of research questions grouped by topic that were of personal interest to me. Thanks to the comments, I recognise that this kind of post is a poor fit for the community. Feel free to use this space to discuss research question generation.