I'm correctly developing my own theme and so far I got: index, header, footer, functions and style files. The list will go on as I'm progressing with my theme. But I'm considering to use more than one theme at this site with total different files and I'm thinking of using simply different names for files instead the original ones, so instead of header.php it would be blabla.php and so on. With different data inside them, of course. So... therefor I have very important questions:
Would this method may make any conflict in WP core or something like this?
get_header
andget_footer
already provide a mechanism for loading different header and footer templates. I suggest spending some time with the Codex and familiarizing yourself with these functions, as well as how the Template Hierarchy works and associated filters.