this is DNS detect failed,it will not influence the network connection. if you can surf the internet,you don't need to care about it.

You can set transmit power to high and set channel width to 40MHz. I think it WiFi will have better signal.

You can check if there's new firmware release for this product.

From your description,it should be a compatibility issue. Usually device and connect to the LAN port and connect to the Internet. I think the only choice is to use wireless network.

Do you mean when you watch video online,the video will buffering or something like it? You can try to make a speedtest and check how much is the bandwidth. If the bandwidth is not enough,it will...

There should be no problem with $. I tried 12345678$ as password and connect with ios 9.3. It connect successfully. Do you set other special character password? Or sometimes input tool may affect...