This site is geared toward understanding the meaning of biblical texts. Therefore, questions not based on a specific text are closed. But there's some older questions hanging around, asked before this rule was in place, that aren't based on a text. I think most of them have other problems as well. Should these questions be closed and/or deleted?
No, I don't believe they should be. In fact, I disagree with the premise of your question above.
This site is geared toward understanding the meaning of biblical texts.
I think it's quite a bit more than that. Specifically I think this site is/should be geared towards exchanging knowledge about field of expertise that is "hermeneutics" and the ways in which that field relates to understanding the Biblical texts. This means there can be two genres of questions on this site. One asks specifically about a passage and how it can be interpreted. These questions have come to be the bread and butter of this site, but even in answering them it is expected of all answers that they do so in such a way that teaches something about the interpretive process. Rather than just giving the answer, they must show their work for how they got there. In doing so they pass on expertise about the field of hermeneutics in general (as opposed to just passing out answers to Bible trivia) in a way that others can later employ on other passages.
This brings us directly to the second genre of questions—ones that ask about the process of hermeneutics directly rather than indirectly by means of some verse. There are less of these out there but I believe they are every bit as relevant to the experts we want to encourage on this site as the first genre and that this format is just as well equipped to deal with them as it is the other sort.
The questions you've asked about are all tagged hermeneutical-approaches. As you might deduce from the questions I've asked to date (look from the bottom), I originally assumed this site was going to be ONLY for that genre of questions and NOT for actually putting it into practice in the form of finished exegesis. I was mistaken then about where people wanted to head, but I don't believe I am so mistaken now when I say that eliminating that genre of question entirely would be to the disadvantage of the site and the displeasure of many experts in the field whose participation is most important here.
Therefore, questions not based on a specific text are closed. But there's some older questions hanging around, asked before this rule was in place, that aren't based on a text.
That's not at all my understanding of the question-scope rules we've worked out. The kind of questions we've ruled out are the ones that ask about theology directly rather than about a text that might have theological implications. In other words a question such as "Was Jesus fully God?" would be off-topic, whereas "What does John 10:30 imply about the nature of Jesus?" would be on-topic. The rule about theology questions being closed if they aren't in relation to a passage would have no effect on a question about hermeneutics itself such as "When did the term sensus plenior become associated with the interpretation of scripture, and how was the concept originally employed?"
I think most of them have other problems as well. Should these questions be closed and/or deleted?
The questions you list (and many others) may indeed have other problems. But they should be dealt with on the basis of those other problems (if any) and not on some categorical basis as if this site was no longer fielding questions about hermeneutical approaches employed in various ways in interpreting Biblical texts. No, I see no particular reason to close any of those questions (although there is always room for improvements to them).