I am being unable to change the address of my topics from one forum to another.
Not certain what you mean - do you mean that, having posted something in the "Official Books" section, you change your mind, and would like to move it to "Curious About Tintin" area?
If that is the case, then I don't believe that option is open to you. It can be changed by a Mod, so you can always ask, but we would ask that members think before they post! :-)
In the posting guidelines, it says that the creator of the thread can close the topic but I am being unable to do so.
Not sure to which of the guidelines you are referring, but if it says that, it is wrong, as far as I know (Irene/ Admin may know more). Again, Mods have the ability to close a thread, but members would have to apply to get a thread closed, and we do that very infrequently.
Recently, whenever I give a URL in my post manually, it does not come on the preview with a space creeping in between letters where I did not give any.
Don't know why that happens (it happens randomly to me), but it seems to have something to do with the length or the way the link itself is constructed. My work around is to use a URL shortening site like Bitly first, then use the Bitly link.