A noisy but well exposed photo is still better than an underexposed or blur photo. Sure, you can PP an underexposed photo to the correct exposure, but that will introduce more noise than using a higher ISO in the first place. I think it's foolish to refuse to raise the ISO when you have to. If I have to use Hi1 on my camera to get a decent shutter speed, I will do it.
Modern cameras can definitely do high ISOs. Base ISO will give you the best results the sensor can give, but that doesn't mean all other ISOs look rubbish.
Saw your pics. The camera has potential but you have to work on your composition maybe 2 times or 3 times harder. You post virtually everything! Sometimes you have to take out the not-so-good ones so that us viewers will have a more pleasant time.
Occasionaly i do use tripod for family and scenary photo.
But most of the time i shoot hand held. I also usually use AFS 35mm f1.8 lens which is good for low light.
For instance indoor,i dail to iso 200 / f1.8 / shutter speed usually about in a range of 50 - 80.
All this is in manual mode.
I also own a D70 and i must says that the D70 perform much better at iso 800. But prefere D3K in terms of picture quality and colours on normal outdoor shoot. And also the size which worth mention as it's small.