question about oil & sending sample to lab for analysis

[paulb]

I've done oil searches here & elsewhere but honestly after a few dozen pages or so I feel like a Neanderthal stuck in the tar pits. I have a couple questions & I'll try to be as specific as possible.

My car is a '04 S with 89,000 mi. has an LN engineering IMS bearing.
It will be a fair weather driver (above 50 degrees f, but mostly summer warm to hot weather driving), garage kept & stored over winters in the Chicago area.

1.
I am changing the oil tomorrow & was going to use 0w 40. Is this the best weight oil for my car & area? If not what would be the ideal weight?

2.
Later this summer I am planning to to the underdrive pulley mod, does this change my oil preference?

3.
I have a test kit to send a sample to blackstone for analysis is it better to do that now, the car is new to me & the last oil change that I see in the records was done 7,000 miles ago but in 2014! Or should I get rid of that old oil & send a sample in in fall when I change it again before winter storage.

Thanks