OLIBRIUS,
as always, you fail to provide (part of) the essential information in a clear way.
> When launching Scribus, it created a new Scribus folder in Preferences,
this part is fine: we now know that you successfully renamed the right folder!
> but it didn't solve my problem...
currently, the first issue you are facing is: scribus takes 10 minutes to start.
the correct information to provide us would have been: scribus still takes 10 minutes to start.
if the sentence above is correct, please start scribus a second time (the first time it might need to index resources like fonts!) and see if it stills needs so much time.
as strange as it might seem to you, if scribus needs 10 minutes to start (not on the first start after having recreated the settings!), then we don't really care if every action takes very long. that is to be expected.
for your information: from what you wrote it could be that scribus now starts in a snappy way, but it still takes a long time to open your document and every action takes very long.
your problem is not solved, of course, but in that case we would have made a big step forward.
you might not see why for me (for us) it matters, but, believe me: the hints we can give you are very different if scribus takes 10 minutes to start without having to open a document or if your specific document needs a long time to edit.
to be clear: here two question i'd like you to answer:
- does scribus still need 10 minutes to start when you double click on its icon (excluding the first start after you have renamed the Scribus directory in ~/Library)?
- and do other program start in a snappy way?
personally, i reiterate my hint to find a person in your neighborhood who knows how to check performance problems on a mac...