Don't stress on exposure times, from here on in you'll be able to push the times up to 10minutes if your tracking is good and not have to worry about noise.

The Sony cooled chip is great! As you can see from your images, no apparent noise!
Yeah that's a close offset/gain to what I'm running. From memory I'm on 4/109.
I haven't even got too pushing the gain as yet. I just use the std. Offset/Gain and image, I think some faint guys will need the Gain pushed up. But for now, your all good, start framing, tracking, and expose'n
Grab your bias frames first, get 30-100, make sure your max in Maxim is 400 to 1000. Do this by checking the histogram.
Set and forget temporarily.
Use them in your processing, and if dust motes/vignetting are apparent during your lights, grab some flats.
First light looks great. Looking forward to seeing some great images from ya