pfSense few questions

Quick question regarding pfSense, relating to this video here

www.youtube.com/watch?v=Q0JFfpG4BWI

I currently have WiMAX internet. I have a WiMAX receiver on the roof of my building with a single RJ45 cable routed into my apartment. The cable plugs into a small power brick. I use another RJ45 cable from the power brick and connect it to my desktop PC.

I have an another old PC that I would like to install pfSense on and have it work as my router, so I can transmit Wifi for use with my laptop and smartphone.

Now I'm assuming all I have to do is connect my old PC with pfSense on it to the WiMAX power brick through 1st Ethernet port with an RJ45 cable. I can then connect an RJ45 cable to 2nd Ethernet port and plug that into my main PC. I also have a TP-Link wireless PCI adapter which I will use to transmit Wifi.

1) Will pfSense work with WiMAX?

2) Can I have wired connection to my main desktop PC as well as transmit Wifi for my laptop and smartphone?

3) Is the configuration described above the correct way to set this up?

Thanks

Pentium 4 3.1GHz

Socket 478 motherboard

512mb DDR RAM

40GB IDE HDD

What do you mean by "Power Brick"? pfsense will run on a network as a router/firewall or in bridge mode. on WiMAX internet what is your equivalent to the modern cable modem? is it something yo can log into and change settings? because if you have a device already working as a router then you will need to set it to bridge mode in order for pfsense to be your router.