What's the hardware version of your router? Make sure you tick Enable Media Sharing. Double check your settings. If you can access the drive another way, then the drive is recognized by the router...

Usually it works with port forwarding. You need to open a port for your internal server, then you can use the DDNS to access the server remotely. http://www.tp-link.com/us/faq-1797.html But be care...

You need to open a port of the PC, then you can use the DDNS domain or the IP address to access the desktop remotely http://www.tp-link.com/us/faq-1797.html And check the Wan IP address under...

not seen this problem on my router. the LEDs were much brighter before? it may be a hardware issue, but if all all your routers behave like that, may be it's how they are designed. some people don't...

doesn't seem to be a way to add a port to the list

there something called allowed port list on the Firewall setting screen, click to show you ports that are allowed when firewall is set to medium or high