Let me say how I do it:
I have the WR802N, I setup to Connect to a Public WiFi-Hotspot and I connect my PC to the Router by means of the WLAN Card.
There is here no cable at all, no modem at all.
EDIT: the WR802N can also connect to Internet by Modem, by Home LAN. It has 4 different working modes, that normally the general Wireless routers do not offer.
If you connect your PC to the xfinity by WLAN Card , you can connect the WR802N to that xfinity too, exactlaly the same way without any modem or whatever, with the advantage that it will show all channels and how strong the signal, and you can choose which channel you want to use.
Yes, that is a WLAN Adapter. You can user the WR802N the same way you use the USB adapter, will do the same thing your USB do, and you do not need any Modem or whatever for that.
You connect the WR802N to the Point which you are connecting now your USB Stick. To connect to Internet you connect the USB Stick to the router instead to the Access Point. Best of all, is that you can connect 100 Devices to the router at same time, you have a Home Wireless Network.
From your PC you have access to the ROuter Configuration and can setup the Working Mode and choice which Channel of xfinity it should connect. Very simple.
My only other issue then is reception. My current WLAN has an antenna on it. It picks up way more than my Belkin N150. Any sense on how reception for this 1 is? If I need better reception, what do I look for in a router? Will any router work?
The Router comes all that what need: Power Supply, USB Cable and Network Cable for to connect to PC, if your PC has one a LAN card, probably it will have. If it has not, you can still access Router with WLAN (Your USB Stick), no problem.
I can not say about Reception, I have not seen any problems, and the HotSpot around me are not the best, they have around 36db so near poor signals. For sure It has a better reception than internal Card on PC.
About "will any ROuter" work as WR802N for your special case, it has to have the function "HotSpot" . The Brindging feature that you find in Most Wireless Routers, I did not succeed in setting it up to connect to Access Point.
I do not know too much about routers, neither I know what the different products offers or do. I that WR802N and I am very happy with it .
The ROuter does not need to be attached to any PC for work, that means you are free to put in a better place, may be near a Window or some place you achieve best reception.
Sorry, still slightly confused how you decribed it, when you said "you connect the WR802N to the Point which you are connecting now your USB Stick. To connect to Internet you connect the USB Stick to the router instead to the Access Point."
So do I still need my USB wifi adapter along with the router or not? Does the wifi adapter capture the wifi hotspot, send it to the router, then it goes from the router to the computer? Or do I just need the router and it captures the hotspot wifi signal and sends it to the computer? Simply replace my USB wifi adapter with the router?
The router is not a replace for your USB Adapter, you still need it.
Let see if I can explain: At the present you use your USB to make a direct connection to xfinity. When using a router, you place the router between your USB Adapter and xfinity. Said in other words, the router will establish a connection to your USB Adapter and also a connection to xfinity and pass the Data to PC and to xfinity. It is some sort of a relays.
Router is a stand alone very small PC, it has its own Processor, OS, ROM, RAM , WLAN, USB Port and so on, and is working for itself , it does not need to be physically attached to a PC for to work, neither is meant to be attached to PC to do its job.
With Router you will get better reception because you can place the router near a Window or in place where the Signal from xfinity is strong and the signal from router to your USB Adapter will be strong enough.