Engine Shut-Down and Clutch

[Nivek65]

I recently purchased an '09 year model. Three things I noticed:

1) The engine runs or idles differently when I depress and release the
clutch. It's almost like I hear a switch when I release the clutch. Is this
normal?
2) When I turn off the engine, there is a second of what I call run-on. A
friend has a new Altima and that motor shuts down immediately.
3) When I shift from 1st to 2nd gear and sometimes from 2nd to 3rd gear I
can distinctly hear what I call the linkage. It is much quieter when shifting in higher gears.

I am not a nuts and bolts guy, but to me these items sound rather odd to me for this vehicle. I have never driven another 370 so maybe these 'noises' are the norm??

Thanks for any input...

Kevin