Hello,
1. I’m afraid that’s not possible with current stable (1.1.1) but I have uploaded a new version (1.1.2) that should use the theme’s 404.php template file if it’s available.
It’s working fine for me using WP default themes. It’s not available for automatic update yet, if you want to give it a try, download it from the advanced view and install the zip file manually from your site Plugins page.
2. The plugin is updated when is needed. It’s a simple plugin with only one purpose, and does its job using WP core functions and best practices, that makes it stable and future proof. Therefore it doesn’t need frequent updates as other plugins.
I know there are many plugin authors doing unnecessary changes to their plugins to have a fresh value for the “Last updated” header, because apparently users think that “Last updated” information is super important. That’s in my opinion a bad practice of those plugin authors, that I’m not going to follow.
Updating a plugin very frequently doesn’t make it better. It’s in fact the opposite, a plugin that works without issues even when its code is not updated since long time, is a well coded plugin.
