No surprise about the security and encryption working better.
I would definitely install the latest drivers for your Samsung, lots of 2012 drivers there that might help.
Support - Notebooks NP305E5AI | Samsung Laptops
As for streaming with wireless G, I wouldn't expect too much as it's limited to 54Mbps although the newer driver might help.
Upgrading to a wireless N router at 300Mbps would be a big improvement although the driver needs to work with wireless N as well.