Sometimes I post some questions on the forum which unfortunately, sometimes, due to some restricting regulations remain unanswered for a long time. I needed an answer to them; that was why I opened a new thread. The question is that if I somehow find my needed information somewhere else during this time and my question is still unasnwered, would it be possible to remove my thread? I wonder if you could let me know about the consequences of removing a recently posted thread with no reply.
Possible deletion consequences
The system already prevents lots of harmful deletions by disallowing deletions from authors of accepted answers and questions that have upvoted answers.
If you delete too many of your threads, it can come off as vandalism, whether or not they have answers. If you delete multiple questions that have a lower score than, say, -3, you'd be in danger of automated question rate limits or bans, but this is extremely unlikely to affect someone with a question record like yours.
General personal commentary
Sometimes I post some questions on the forum which unfortunately, sometimes, due to some restricting regulations remain unanswered for a long time.
It's a bit vague what you mean by "restricting regulations". Do you mean they get closed, or that there is an awful lot of comment–answering on them?
Anyway, have you ever considered you could improve the way you're asking your questions? They are typically very well-formatted, which is a good thing! However, they usually follow few very rigid structures and there is no creativity in composing them. No one owes you an answer, and the onus is on you to try and make them interesting enough to spark some genuine interest in answering them.
For example, as I've picked up for a few years and as I go through your lower voted questions, I can't help but notice the very common patterns when you aim to compare two or several words (1, 2, and 3, each representative of the style you apply to numerous other questions). Occasionally they're interesting because of the words you choose to compare, but
- using the same style tends falls flat if you want to get people to check them out, and
- almost every time you don't get a positive reception, it's because, although you tend to establish the context very clearly, and demonstrate your effort, you usually don't explain why you're comparing them, or why they're confusing you.
The second bullet point is very important IMHO. Your questions suddenly run out of energy as soon as it gets to explaining your source of confusion, and that renders some of your comparison questions very bizarre, hence making answering them a moot point.
Having said all that, frankly, the chances of resurrecting an ignored question standing at a negative score are pretty slim, so by all means go ahead and delete a couple every now and then if they are indeed hopeless, but please give them a chance if they're already answered, so as to respect the answerer's time and effort put into it.
I also second Colleen's suggestion on writing self-answers. Besides the delicious reputation gain from contributing quality posts to the site, there is the warm and fuzzy feeling of helping a fellow ELL who's just confused on when to use "incidental" and when not to.
References / Further reading
It would be better in my opinion to write an answer for it so that someone else with the same question can benefit. There is more discussion about answering your own question on the meta site for all of Stack Exchange: Can I answer my own questions, even if I knew the answer before asking?