SOLVED.
1. Problem unrelated to Slackware or wget: Installed a new docsis 3.0 modem a week ago and my wget attempts were the first time I tried to reach the internet via the router/firewall/server box. Seeing the strange Comcast activation message in the index.html file led me to try reaching any internet address. Tried links
http://www.google.com and received another odd http error message from Comcast. At this point, I figured a reboot might help. Upon reboot, the device was recognized and/or "activated" by Comcast --- have no idea what that's about, but that's another issue.
2. Tried the following wget command: wget -v -r -np
http://mirrors3.kernel.org/slackware/slackware-14.0/
This also failed, but I received a file titled "robots.txt"
Googled wget robots.txt and added -e robots=off to the above-stated command and it seems to have solved everything.
Entire slackware-14.0 directory is downloading as I write.
Thanks for your patience.