So many questions, where do I start. j/k

In your post you said that you wanted to edit out some deat time from the game. With a DVD camcorder like the dcr-dvd505 editing will be very difficult. Usually people who want to edit go for the MiniDV format. None of the dvd camcorders that I know have a firewire connection. Firewire allows you to capture the video without any more compression so it's a higher quality. All miniDV ones have it so editing is easier with them.
The DVD-R discs can't be changed once they are recorded. You can not edit the DVD. I think the DVD-RW and DVD+RW can be "edited" only through the camcorder but it has to be done before you finalize the disc.(get a second opinion) However this is not true editing. The camcorder records the video in small clips, the only thing you can do is delete some of the clips your don't want. You can't delete half of a 3 min clip and keep the other half.
The DCR-DVD505 is good in low ligh. The sony dcr-hc96 is the sony top of the line MiniDV camcorder and that is just as good in low light too. Retail price for it is 799USD. Also you don't have to use a computer to make a DVD from the HC96. Do you have a DVD recorder that you hook up with your TV? If it has a firewire input you can connect it to the firewire on the HC96 and make a DVD disc.
In my opinion get a miniDV camcorder, but retail price for the DCR-DVD505 is 1099USD so you did get a good deal on it.