Delete old stuff
I feel that the interface is slow and I suspect the reason is that my feeds have many entries.
I think it would be great if you let me configure on a per feed basis if I want old entries (ones I already read) to be kept or not.
Most of my feeds are about things I don't care about after reading, so I want them to be deleted if that will speed things up
The interface is slow, because of the code performance and number of simultaneous users on the current hardware. TOR doesn't preload any posts at all. When you open folder or feed it loads around 30 feeds and after you scroll down it loads more. Your "undeleted" posts don't have impact on the performance.