Community support and boost

[macsa]

I'm not sure this is a new idea, but I'm sure it can make the torrent community much stronger.
Even I can see somebody seeds the requested torrent many times I have to wait for downloading it because - I suppose - it is not started on the client.
Also many times, when I 'just for try' start an offline torrent then I can see the download starts asap, because some people waited for downloading it. My idea is if I can realize this request earlier then I can seed it earlier.

Based on these two situations I have the next suggestion:
It would be great, if we can build a catalog from those torrents what we already deleted from the torrent client but we have on the disk or on an offline disk (so we do not seed them at the moment but the client could be decide we have this torrent). And also it would be good if we can set that if we have an offline torrent what others want to download then we would like to get a message, so we can help them asap.
Also, in the client we should have a setting or a control next to the torrent where we can set the seeder notification. So we should have have a possibility to turn off this feature.