Hi there,
To centre the title you can use the following css slector:
#sitewide-notice strong {
text-align: center;
}
However currently it’s not possible to separate the two paragraphs. This is due to the text going through the wp_filter_kses() function which is removing the <p> tags from the text thus turning two paragraghs into a single paragraph.
You could ask for an enhancement in Trac, to change this to an alternative function bp_messages_filter_kses() this would allow you to add a filter to allow <p> in the sitewide notice content. If you raise the ticket I’ll add this information as a suggestion to the devs.
