Use ENTER, not SHIFT+ENTER to Insert Line Break in WP editor

While i didn’t exactly look into TinyMCEs code, my assumption is the following:
Without using the above code, TinyMCE closes the active p-tag and opens another one on pressing Enter. When you use the above code, this is replaced by NOT opening any p-tags and just inserting
tags when you press Enter.

The Alignment-Buttons probably try to find the p-tag, which encase the current text and add an style-tag (text-align:left). As there is no p-tag, the style can not be added and the text-align buttons “do not work”.

IF it is like this, there is no way of “repairing” this behaviour without pretty much editing TinyMCE.