I'll leave my opinion out of this....
1) The latest version of the Blogs Made Simple module is only available via XML file. Which means you have to have your Modules directory writeable by the web server. Which means (in a lot of hosting environments) that once it's installed you, yourself cannot edit any of those files (by default).
If you can't edit the file, you'll need to use something like this:
Save that as a php file that you can access on your website via your browser. Then you can edit the file.
2) The date format it pulls up is hard coded in the module, there is no setting for this. It's obviously a personal preference of the developer.
You would edit line 490
Change:
$datetime.=date("H.i",$unixtime);
to:
$datetime.=date("h.i",$unixtime);
That would give it a 12 hour time. See this page for more options:
http://us3.php.net/date
Once done, I would probably set the permissions on the file back to the way they were, probably 644