Right now, we don't even have a target audience :) hah. I agree about the issue with the enter/button.

We were going to have the marks load but be hidden in default and then users could change the setting to one or the other either universally or with each image.

We definitely will be limiting number of marks. Actually, in the long term the marks/feedback etc will be more curated based on latent semantic indexing of comments/content (once we move into text, etc) and a variable assigned to the commenter (or marker) based on number of similar projects having commented on. More here: http://kelseyfalter.posterous.com/stop-posting-start-reactin...

Ps. Thanks for your input! You really have no idea how much I appreciate it.