Hi,
1. That "drop window" feature is not planned.
EDIT
I totally forgot about this feature (probably because I never used it)... See the post below this one (thanks mgpai!).
2. Our myjdownloader browser extension was supposed to get these features added.
This has been delayed for a long time so please do not expect any progress regarding this in the near future.
You can use other browser addons to help copy/catch download URLs of e.g. video streams to be able to add them to JD e.g.
Video DownloadHelper or similar.
-psp-