The firewall on your laptop may be blocking ICMP echo-replies. Try temporarily disabling the firewall and see if it solves the issue, if it does create a firewall rule to allow ICMP.
I used the G110 (the predecessor to the G105) for about 5 years before I went mechanical. It was great for the price, and my brother still uses it now.
Your best bet would probably be to get multiple wireless access points and place them around the house to separate the devices. I really like the ubiquity stuff.
some USB hubs come with a 5v power adapter that you plug into the wall, for extra power for devices, as to not burn out the port on your computer. I would recommend one of those if you are plugging high-power devices into the hub.
could be the power supply. Mine does that occasionally. Usually a couple taps on the side of the case will make it stop. I think i need to get some rubber or something to stop it vibrating.
It's also possible it's the NIC on your computer. That's what my high ping problem. The only way for you to really nail it down is to swap out the possible issues one at a time.
I'm 17, and will be moving to Burnaby in September to get a diploma in Systems Admin from BCIT. I have been tinkering with computers my whole life, and have done a few build for friends, i'll edit this post with pictures when I get home.