As a regular user of the Wordl thread, I would have absolutely no problem with this.
We’ve had the debate about political threads for years and everybody seemed OK when we agreed they should moved to a separate permanent folder at the top of the page when they got too long.
Putting them in the existing Prediction League folder wasn’t ideal but I seem to recall it was the least worst option at the time.
The problem with letting them sit on the main page tends to come more when we’re in the season when they have sometimes clogged the main pages and pushed football related stories out of view.
With regards the Southport thread, if the poster who opens a thread asks me to close it I usually do. That may be right or wrong in anyone's opinion but I try to be consistent.
With respect to political threads, when they were proliferating on the board the decision was made to move them off to the Prediction League board where they typically withered and died. Unfortunately the moderators don't have the rights to rename a board so it's naturally confusing. I toyed with moving some of the recent posts over there e.g. Brexit/Immigration March but decided to leave them as Dukes Bar is pretty quiet at this time of year.
Regarding O/T in general. If I see an O/T post without the O/T I usually add it and remind the originator to do the same in future. We did once move all O/T posts off the main board and as a result the whole site almost died due to lack of interest. As mentioned, it's not hard to ignore a post if you know it doesn't interest you e.g. Wordle or if you really are only here for the football (many aren't as they enjoy the general chat/camaraderie) just ignore all O/T posts.