I used a different workaround for bug 3 (Text shifted to right after a br tag in centered text).
If you add a at the beginning and ending of the line, the text stays centered. In this way you don't risk to have the text moved left using a different viewer.
<p style="text-align: center;">This is a normal line<br />
(this one will be moved right in ADE)<br />
(this one should be centered) </p>