Hi Bleak,
1.The PHP code was not using MysqlI on PHP 5 and the modules where doing very inefficant calls to the db and not caching queries that should of been
ExpressionEngine absolutely has the ability to cache database queries. Due the to dynamic nature of the system, not everything can be cached, but ExpressionEngine is very efficient in this area, and cached queries can be served very quickly. I’m not sure what specific queries they felt weren’t cached, but we’d be happy to comment on these if you had more details.
2.It was not using MySQLi ...only the old MySQL connection methods
This is true. MySQLi is only available for MySQL versions 4.1 and up, but ExpressionEngine can run on MySQL versions as low as 3.23.32, so for compatibility reasons, we use these. Also the MySQL connection functionalities are much more widely supported then MySQLi. While we are looking at expanding our database capabilities, currently EE requires MySQL extensions.
3.The mail system at that time did not support SSL connections
I’m not sure what they are pointing out here. ExpressionEngine supports sending mail via the native mail() functions, via sendmail, or via SMTP. If you could tell me how your host would want you to use email, I could tell you if EE supports it, but my hunch is that if they allow PHP scripts to trigger email, then ExpressionEngine could almost certainly handle it.
One other thing is that it sounds like this host has implemented these restrictions for the sake of security, performance, or both. I want you to know that ExpressionEngine takes both of these aspects of design very, very seriously. I invite you (and your host) to audit our security record (a single, mostly theoretical hole in the entire life of our product) vs say, WordPress, or Drupal.
Performance wise, we cache generously, but more importantly, allow for for designer and programmer control, so that they can implement choices that best suit them.
If we can answer anything further, don’t hesitate to write back. Also, I’m moving this into the presales forum to ensure that all the right eyeballs are on it 😉
Derek