1. We have no such setting but I know what you mean.
You should be able to archive your goal via Settings --> Packagizer --> Create one or multiple packagizer rules for what you want.
2. We do have Crawl plugins for a lot of site but the forum site you mentioned above is NOT supported by any of our plugins and won't be in the future BUT this doesn't matter.
This only means that you will need to add each page "by hand":
xxx.xxx/foro/showthread.php?t=12345678
xxx.xxx/foro/showthread.php?t=12345678&page=2
xxx.xxx/foro/showthread.php?t=12345678&page=3
...and so on.
So at the moment I do not exactly understand what you mean because we haven't changed anything here (or I didn't notice that).
The only thing I could imagine is that we have some other default settings now but the site you mentioned above was NEVER supported via plugin in JDownloader so there is NO WAY that JD actually "walted" through it and decrypted e.g. all pages of a forum-thread.
GreeZ psp
EDIT
What you CAN do (this was not possible in the past) is that you can make your own Crawl-rules which basically means you can force JD to deep-crawl links matching a specified pattern so then you can easily add the above mentioned "page-links" with 1-2 clicks.
HERE I posted some hints on how to do this.