Thanks for your interest in contributing to the Plogger project.
Are you doing your development on the latest stable version (1.0beta3) that was downloaded from the main website page? If so, that version is old. The project code has changed considerably since that was released, including bugfixes, new features, and a complete restructuring.
In reading your list, I see at least one thing that has already been added to the latest SVN version - the link back to the main site on the login page. In fact, the entire login page was redesigned, with new features incorporated. There are other new features in the latest SVN version that you may not be aware of that would impact the things that you are currently developing.
I would recommend that you download the latest SVN version using a Subversion client, such as TortoiseSVN, and do your development on the latest SVN version. That would allow you to create patches that can be added to a Trac ticket for the dev team to review, test, and then decide whether to add them to the core or not. Using Subversion will also allow you to stay up-to-date with the latest code available from SVN much easier.
I would also recommend reading the Trac Wiki for developer information. One link is to the (still under development) Codex regarding reporting and patching bugs. The other link is to some Plogger developer standards.
You're more than welcome to contribute patches (you can open a ticket for each patch you create). We encourage people to join the development and make Plogger even better.