Questions regarding overall setup.

[kilburn]

1. No, you shouldn't. The performance increase is negligible under a usual Web/e-mail server workload, and it will surely cause issues when upgrading the panel.

2. Ispcp is a vhcs2 fork, a project which started back in 2001, while dovecot started sometime around mid-2002. Migrating from courier to dovecot is not a 100% transparent process, and we're studying the best upgrade-path possible to switch to dovecot as default. Until then... I also recommend you to stick with courier.

3. Ispcp is fairly secure by default (when compared with other hosting panels), but everything can be hardened further. Take a look at how to make ispcp more secure, and/or the other security related howtos from the docs page.

a. Policyd-weight should be enabled after a default install. Whether you should run it or not... depends on your preferences. Read about what it is/does and choose by yourself.
b. IspCP Daemon should DEFINITELY be shown as running. Is your panel really working? (try to add a domain, for example)
c. amavis is an anti-{virus,spam} platform, so your preference again.
d. Postgrey implements greylisting for your mail system. Personal preference again...