Seperate tab for verbose logging (instead using "aMule Log" for everything).
Dunno, sounds reasonable to use a "everything" and a "only important things" log window.
Regarding the upload slots: There's no real advantage, except for new releases, where getting chunks of one file to many seeds fast is more important than spreading many files to many users.
I upload with 8KB/s each to 5 users, so it takes about 20 minutes for one chunk to be uploaded. Now I can upload again to new 5 users AND these 5 "old" users can upload as well. So after 40 minutes, I've uploaded 10 chunks to 10 users, which can spread them already, and IF the 5 first uploaders upload the same I do, my chunk has been uploaded 10 times by me and 5 times by each of my 5 first downloaders, equals 35 times in total dring these 40 minutes. (This is purely theoretical!)
If I upload at 3KB/s, I have about 14 upload slots and uploading one chunk takes about 52minutes. It takes longer for my chunk to spread, but it will be more widespread.
The end result is about the same (I upload the same number of chunks to the same number of people), but if I disconnect after 50 minutes there's less harm done (unfinished chunks) when I upload with a higher speed per slot.
I personally see an advantages if you download few files as well, but that depends on too many ifs and whens, that it's more of a personal preference thing.