Update defaults to what I consider "smarter" values, or even a preset selection page.

Call this the shared hosting preset. Site gets updated several times a week, updates are not time critical and only the admin has a login. This turns the cache up to the max, disregarding just about everything else. Reliable cron; no poormans; or rules cron run trick.

// Dir & File Structure
define('BOOST_NORMAL_DIR', 'normal');
define('BOOST_GZIP_DIR', 'normal');
define('BOOST_PERM_NORMAL_DIR', 'perm');
define('BOOST_PERM_GZ_DIR', 'perm');

// Caching Options
define('BOOST_CACHE_XML', TRUE);
define('BOOST_CACHE_JSON', TRUE);
define('BOOST_CACHE_HTML', TRUE);
define('BOOST_CACHE_CSS', TRUE);
define('BOOST_CACHE_JS', TRUE);
define('BOOST_PUSH_HTML', TRUE);
define('BOOST_PUSH_XML', TRUE);
define('BOOST_PUSH_JSON', TRUE);

// Advanced Settings
define('BOOST_ASYNCHRONOUS_OUTPUT', TRUE);
define('BOOST_GZIP', TRUE);
define('BOOST_AGGRESSIVE_GZIP', TRUE);
define('BOOST_CLEAR_CACHE_OFFLINE', FALSE);
define('BOOST_HALT_ON_ERRORS', FALSE));
define('BOOST_HALT_ON_MESSAGES', TRUE));
define('BOOST_CACHE_QUERY', TRUE));
define('BOOST_IGNORE_FLUSH', 1);
define('BOOST_OVERWRITE_FILE', TRUE));
define('BOOST_DISABLE_CLEAN_URL', TRUE);
define('BOOST_FLUSH_NODE_TERMS', TRUE);
define('BOOST_FLUSH_CCK_REFERENCES', TRUE));
define('BOOST_FLUSH_VIEWS', TRUE);
define('BOOST_FLUSH_VIEWS_INSERT', TRUE);
define('BOOST_EXPIRE_NO_FLUSH', TRUE);

// Crawler Settings
define('BOOST_CHECK_BEFORE_CRON_EXPIRE', TRUE);
define('BOOST_CRAWL_ON_CRON', TRUE);
define('BOOST_CRAWL_URL_ALIAS', FALSE);
define('BOOST_LOOPBACK_BYPASS', TRUE);

Creating a "wizzard" instead of various presets might be a good idea, so it asks the user questions and guides them through the setup that matches their configuration, grouping several settings into 1.

Here's my todo list.

Actually there is only 2 question that control how boost should be setup...

Do you wish to use the cron crawler?
If Yes then Enable.
* Overwrite the cached file if it already exits
* Expire content in DB, do not flush file.

* Enable the cron crawler
* Do not flush expired content on cron run, instead recrawl and overwrite it
* Preemptive Cache HTML
* Preemptive Cache XML
* Preemptive Cache AJAX/JSON

Is this an i18n site?
If Yes then Enable.
* Do not store the cache file path in the database
Disable
* Only allow ASCII characters in path

The rest should be "smart defaults" with "Turn off clean url's for logged in users" disabled even though it can give the end user a performance boost.

Going to ship with Crawler disabled & i18n disabled.
Updated Defaults.

Adding the info into the documentation sounds like a good idea. readme.txt, handbook, both?
With these defaults, this is the new wording

Do you wish to use the cron crawler?
If Yes then Enable.
* Overwrite the cached file if it already exits
* Expire content in DB, do not flush file.
* Enable the cron crawler

Is this an i18n site?
If Yes then Enable.
* Do not store the cache file path in the database
Disable
* Only allow ASCII characters in path

The rest should be "smart defaults" with "Turn off clean url's for logged in users" disabled even though it can give the end user a performance boost. I'm leaning towards not caching xml/json by default after discovering voting api stopped working if caching XML. I have that fixed now, but how many other modules out there would be incompatible with boost out of the box?

made changes to the htaccess files

Committed. Added this to the readme.txt file.

CONFIGURATION TIPS
------------------
i18n, Domain module:
  Enable
  [x] Do not store the cache file path in the database
  [x] Flush all sites caches in this database (singe db, multisite)
  Disable
  [ ] Only allow ASCII characters in path

Enable XML & AJAX/JSON caches
  Enable
  [x] Cache .xml & /feed
  [x] Cache ajax/json

Use Cron Crawler
  Enable
  [x] Overwrite the cached file if it already exits
  [x] Expire content in DB, do not flush file.
  [x] Enable the cron crawler