It's hard to encapsulate every db configuration value into a Feature. And, Features was never designed to do that. A Feature was originally supposed to be a re-usable site component.
To capture more fully site configuration look at the Configuration module:
The configuration management module enables the ability to keep track
of specific configurations on a Drupal site, provides the ability to
move these configurations between different environments (local, dev,
qa, prod), and also move configurations between completely different
sites (migrate configurations) without the use of modules with all
configuration being owned by the site.
For the most part this module provides the same functionality as a
subset of the features module. Features module is currently the go to
tool for moving configuration from environment to environment and site
to site, and it does a great job doing this, but "configuration
management" was never really what features was intended to do. The
goal of features module was to group configurations together to
satisfy a certain use-case. Instead most people use features to export
configuration to code to ease with deployment between environments.
Many of us have experienced the shortcomings of using features module
for configuration management and found where it doesn't quite work to
easily manage configuration. A couple other modules have spawned off
to help with some of these shortcomings: features override, features
plumber, Features Tools.
Additionally since not everything can be captured in Features, look into building your site via a
Installation Profile where you can codify new Users, Content Types and custom variables as well.
I am currently using Features + an Installation Profile to build a webapp that lets notified individuals via email submit a Drupal Webform via a secretly keyed url parameter. You can use features (to an extent) but you really have to use many small features to get the job done, and not all modules play well with Features (like exporting Webforms, which requires node_export, uuid and THEN features) ...