And look at every comic page on this wiki. They all have three date categories. Month (based on coverdate), Publication Month and Publication Week. Changing the Month and Year fields changed the publication categories, making them indicate that Justice League (Volume 4) #37 was published in October rather than December.
The PE boilerplate should always link to the original version of a character. In the case of Thomas Wayne, that's the Earth-Two version. This also applied to the Adapted boilerplate.
Pro tip: if you upload a cover that is PAGENAME.jpg, you can select Quick Template from the license dropdown. It adds the source and fetches the cover artist.
No. The era or "Age" in which these characters debuted is known on this wiki as the "New 52" era. It is the age following the Modern Age. All characters introduced after 2011 fall into this category.
I'm going to run the bot through category creation/deletion when I've emptied the Move category, there's no need to do it manually and pollute Recent Changes.