answered several times already but will I feel good today to answer it once more
The 0/XYZ means that 0 of the loaded URLs from site list are new to the project. Means it has submitted to that sites before and will not waste any time on it. You have probably disabled search engines or have this project on status "Active (site lists only)". Set it to Active and enable search engines again.
I don't get your question really. If projects have seen that URL and worked with it, they don't try to place a link again of course. And if you clear target url cache and history, they will try to submit again.
And if you have search engines enabled this will only appear in log when no search engine results are found to submit things to.