For the "Application list is partially refreshed some catalogs unavailable. Check catalog details." message, freeing up rootfs space might help a lot.
See this wiki page for useful tips. (The "alternate script" helped me the most. Run that, and the optify python steps, and perhaps optify the welcome applet, too. Then you won't have rootfs issues again.)

As for boot videos, just search this forum. There are plenty of them.