Lots of questions.
You can record the analog outputs of the Dish 722 receiver. A TV tuner, if an analog/digital combo, usually can record NTSC input signals, including the RF output of your 722, or the S-video or composite, all of which are SD and not HD. If you want to record the HD component output, you will need an HD DVR of some sort such as the Hauppauge. I know of no way to record the HDMI output since it's encrypted.
As for watching the TV2 outputs, you most certainly can feed it to multiple rooms. There are two modes for the receiver to operate in; the one where the two outputs are independent is called "dual" and is the default. So any TVs viewing the TV2 output will not interfere with somebody else viewing the TV1 output. The only confusion here is when something is being recorded, and there are two modes of operation here as well. The simplest to understand is the mode where a recording scheduled from one TV is recorded on that satellite tuner. the other mode shoves the recording over to the other tuner, and we just hope that nobody else is watching at that time. If you don't have collisions, this makes it possible for either TV1 or TV2 outputs to record something while watching something else live. If you do have collisions, then something has to give.