nextgen-gallery – NextGen gallery SEO question

Hello!

I have 2 questions:

1. What permission do I have to set to the gallery folder? I changed the ftp and it doesn’t work anymore, it says the directory is not writeable, it’s currently 755, if I set it to 777 it works, but doesn’t that make my directory vulnerable to hacker attacks?

2. When I add a gallery, I can set up a description and tags for that gallery(in the # Manage Gallery section). Are the tags and description SEO-friendly or they don’t matter at all in search engines, they are just to allow me to find a certain gallery quicker?