No, currently there isn't any upload limit. However please upload within reason. I'm just one guy, I don't have unlimited funds.
If you've selected one of the options (auto-generate token or enter a password) then you can use the "Delete?" option at the bottom of either the album or image page.
If you have a registered account(no email required) you can delete images/albums without the need for a token or password.
If you didn't select either of the options previously mentioned then I'm afraid there's no way to delete the image(you can send me an email or something and I'll see what I can do - see next question).
I take privacy very seriously. I don't track or ever plan on tracking any activity on this site. The register option doesn't require an email and it never will. If you have questions or concerns regarding this, please feel free to email me(firstname.lastname@example.org) and I'll get back to you as soon as I can. You can also find me on reddit.com/user/DE-8yO3fnJ4/ send me a message.