1) The GeoLite database is very limited. It'll usually give you the right country, but that's it. (And there can only be one database in use by the module, so users can't install their own licensed GeoIP databases.) The utility simply doesn't justify the technical cost of installing and loading yet another Apache module.
3) mod_spambot isn't configurable on a per-site basis, and it would be completely inappropriate to enable by default. It also tries to do a few insane, unreasonable things, like send the site owner an email every time someone gets throttled by it. Here's a couple choice comments from the source code:
* TODO: Improved handing of vhosts, and test .htaccess works
* FIXME: Currently the dbfile needs to be truncated manually before startup
* when the default name (/tmp/spambot.db) is used
* FIXME: this is per server, should be per directory
static whitelist *whitehead, *whitelast;
* FIXME: this linear search will be slow for large sites.