It's best not to move from one server to another, but rather do a fresh installation.
you can then export the products and CMS tables from the old server using phpMyAdmin, then import that data to the new server.
you say:
"1. What procedure is best to move to new server?
Attempt to fix issues on existing server
Move site to new server, then upgrade, then test
or ?"
if there are issues on the old server, it is no good to move to a new server without first fixing them, don't move a broken site, you'll just end up having to troubleshoot on the new server.
if you must troubleshoot the on the new server, a blank page means that a php error is occurring but error reporting is turned off.
to turn error reporting on, add the following code at line 1:
<?php
error_reporting(E_ALL);
ini_set('display_errors','on');
?>
once we know what the error is, we will be able to troubleshoot the cause.