Yes, it is a little difficult to use,

The posting editor is using a format similar as MS Word. Since you copied the content directly from a website, the format information also comes with the content, and it will interfere with the formatting function of the forum editor when you paste the content. This is why you got messy content.

I guess you ever met following embarassing situation: you copy contents from a webpage, then directly paste it to a MS-word, you will find it a little difficult to edit the format in Word, since the website format interferes with Word formatting function.

Generally, the best way is: you create an empty pure text file (with extension .txt or .dat), then copy the website content first to this blank text file. This process will filter out all embedding format. Then you copy this to forum editor (or your ms-word), you will find it much much easier to edit the content and assign format to it.

Hope this solve your problem.

I may replace current posting editor with another for easier input.

Or, the simplest way is, I disable the enriched text editor, and only enable plain text editor. In this way, it would be very easy to form paragraph of the text, but there is no function of format.