[Angel-Wings]

That depends on your configuration and if you maybe run other sites on the server and if any modules have been built in. VB itself won't need much.

LoadModule auth_basic_module libexec/apache22/mod_auth_basic.so
LoadModule authn_default_module libexec/apache22/mod_authn_default.so
LoadModule authn_file_module libexec/apache22/mod_authn_file.so
LoadModule authz_host_module libexec/apache22/mod_authz_host.so
LoadModule authz_user_module libexec/apache22/mod_authz_user.so
LoadModule charset_lite_module libexec/apache22/mod_charset_lite.so
LoadModule log_config_module libexec/apache22/mod_log_config.so
LoadModule logio_module libexec/apache22/mod_logio.so
LoadModule mime_magic_module libexec/apache22/mod_mime_magic.so
LoadModule unique_id_module libexec/apache22/mod_unique_id.so
LoadModule setenvif_module libexec/apache22/mod_setenvif.so
LoadModule mime_module libexec/apache22/mod_mime.so
LoadModule dir_module libexec/apache22/mod_dir.so
LoadModule actions_module libexec/apache22/mod_actions.so
LoadModule alias_module libexec/apache22/mod_alias.so
LoadModule rpaf_module libexec/apache22/mod_rpaf.so
LoadModule auth_form_module libexec/apache22/mod_auth_form.so

These are mine but even this can be stripped down - really depends on your server configuration. Except rpaf / auth_form all modules are Apache's own ones.
Rpaf is used because of my reverse caching proxy, auth_form handles SSL encrypted logins for VB.

The easy way is maybe removing one-by-one on your test environment - not the production machine - until something is broken.
And check the official Apache documentation - mod_alias will be needed if you use any "alias" directives, if you don't, no need to use this module.

And - additionally - don't forget PHP and MySQL. Won't give a much better perfomance if your Webserver can deliver pages lightning-fast if the Database slows down everything. But for PHP and MySQL - depends on your usage.

tuning-primer / mysqltuner can help for MySQL and maybe some Profiling tool for MySQL to see if any Addons cause problems with long queries.

And for PHP - you won't need the openssl extension as example if you only use VB and don't use any SSL / TLS - e.g. for sending mails over a SSL / TLS connection. And a memory_limit of 128 MB might look good, but is pretty useless in the most cases.

If you still have some spare resources, a reverse proxy might help to speed up things - specially static content like JS / Images and there, yes, Nginx might be a good choice.

Sorry if there's no clear answer, really all depends on how your site and VB are used.