#1 : Currently there is not field which support html entities. We need to work on editor type field to support html, it may take some time. I hope you are not in too hurry.
#2 : You need to copy the file from Joomla => components => com_joomprofile => extensions => profile => templates => site.profile.search.result.php to Joomla => templates => yourTemplate => html => com_joomprofile => site.profile.search.result.php
and remove that code of joining date from this new file