Re: Bum Install?
#1. I see that you’ve installed WP 3.1 RC3. Unless you’re developing and/or interesting in debugging, you should install stable version of WP 3.0.4 which is what you’ll get in download here https://wordpress.org/download/. I recommend reinstall from scratch – clean database.
#2. Re Gallery plugin you installed – PhotoSmash Gallery plugin. I haven’t used the plugin and do not know whether it’s compatible with BuddyPress in terms of allowing users to upload media without going to the backend/dashboard i.e. uploading images in posts. There are free and paid Gallery plugins which are compatible with BuddyPress.
BP Album +: https://wordpress.org/extend/plugins/bp-album/
BuddyPress Media Component with KalturaCE Suppor: http://wpveda.com/buddypress-kaltura-media-component/
BP Gallery (paid): http://buddydev.com/plugins/bp-gallery/
#3. How young are the kids you’re expecting to post in your site? In relation to that, won’t you need parental permission for kids to enter your site? Different laws for different states/countries.
#4. I suggest changing your admin username and password. Anyone can come in and mess around in your site – though I appreciate the pass since I saw right away what WP version you’re using and Gallery plugin you installed 
