I'm ok with the 3-pic cap, but thats 'cause I'm not very productive (seriously, just 4 pics in 3 months!), and I think for many ppl here, 3 per day is enough, because not every day is a photo-taking day, and even if you took a lot of pics (I mean the posting-worthy ones), you could space them or plan a schedule, hehe...

BUT
there are some that are very productive and will eventually get overwhelmed with unposted pics because the 3-pic cap isn't enough, or some that are not THAT productive, but the only chance they got to post (due to work, life, etc.) they have more than 3 pics. In both cases they'll have contant acumulation.

So, maybe a 4/5-pic cap with the criteria already in use (and the ones mentioned above). In the case of photos telling a story, you could opt for a daily/every 2 days episode, or post the first episode (photo) and post the link to a imagehost site, like the "Adventures From the Roll Top" dios...

(and lastly, I tried the "delete" tip on one of my photos, but it said "you don't have the privileges")