Yes .htaccess can give added security but be careful as I've run into recently on a Gentoo configured host with Apache 1.3
Certain modifications to .htaccess can cause browsing to become enabled. Host provider had to restart Apache to fix one thing, then when I made some other changes it broke it again. I had to put back the previous settings to keep it locked down.
Not sure if it's some fluke on Gentoo or what but weird. Just make sure you double-check your folders/files still work as excepted once you make changes to .htaccess
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