Bitcoin Forum

To have a ToDo before the logout in the menu bar, where a user can have a text area for working purposes.
1. It can be used as bookmark to save links to important or to be merited posts.
2. Used to list and track progress of tasks to be accomplished.
3. Working space for campaign managers.
4. Can encourage work on the site even when not close to a computer.
Thanks!

You can use bookmark from browser or spreadsheet to save those information. Personally, bookmark is better and more convenient than spreadsheet.

It is for personal task and you can you use Trello (https://trello.com/home).

Forum does not involve in campaign/ bounty management so managers have to do their works to get income.

While a "favorites" list might somewhat make sense (to cover at least your point #1), the rest are not actual features for the forum, hence I would not have too much of hope for a ToDo space getting implemented.
#1. can be handled with browser bookmarks, just make a "folder" just for this purpose
#2. I guess that your best option is 3rd party software/website. This can even help your privacy on bitcointalk.
#3. Campaign managers better use for their work either offline tools, either tools that save everything *very* often; a text box can too easily lead to things (work) getting lost.
#4. Sorry, I didn't understand what you meant.

Noted! Thanks for this Trello (https://trello.com/home).

I meant that if such provision as ToDo is added, I can save some of excel work there, some unused data and text. Such that if I am not close to a computer for whatever reasons, I can login with my mobile, edit already saved complex files and post.

In that case I strongly suggest you consider a tool that saves the data (very) frequently, like for example Google sheets (but I've only used it from laptop, so maybe you find something better for mobile) or even an e-mail tool (write as e-mail that you will never send).

Yes, thanks, @tranthidung has suggested to me. It's fine that way. The feature might be insignificant to be incorporated but could be insightful on privacy base.

I agree. "Favorites" list could be useful, or some other way of highlighting interesting topics / posts. Much like we have a "Watchlist" on the current forum.
My only complaint is that, currently, all threads I've ever replied to are automatically added to my Watchlist, and because of this, it is extremely cluttered, making it unusable.
It would also be nice if there was some space for private notes as well.

There's also a Google Sheets app for both Android and iOS devices ^{[for the most part, it works pretty well]}.

If privacy is a concern, then you might want to read the following link: About privacy (https://bitcointalk.org/privacy.php)
^{- Adding any of the above suggestions would result in little to no impact on the privacy front.}

You can remove them from your watchlist:

• Watchlist (https://bitcointalk.org/index.php?action=watchlist) > Edit watchlist (https://bitcointalk.org/watchlist.php) > Put a checkmark on those that you want to get rid of > Click the "Remove checked" button.