Geo -- Congrats again on the lens. I struggled with many of the same questions when I first started using my macro lens, so I'll try to answer some of them.
1) If there is a "rule of thumb" for aperture with macro shots its that the closer you get, the less DOF you get for a given aperture. So you get to very small apertures very quickly in an effort to keep more of your subject in focus. People that shoot a lot of macro fight this by getting lots of light into the picture (some camera makers manufacture flashes that attach to the end of the lens to blast the subject with light). If you are indoors, as you were, then you don't have to contend with a breeze blowing your subject around so you can just use a long exposure. A good bright worklight next to your subject also works wonders. Getting the aperture too small (f/number too big) can lead to diffraction issues which sacrafices sharpness. The cutoff for this is different for each lens, but if you're approaching your maximum aperture then it's likely to be an issue. In your picture f/8 seems a very good choice. If you were to get closer to the rose, you would probably need to make it a higher number, as you would rapidly loose DOF.
2) True macro is defined as a 1:1 reproduction ratio, so I agree this is more of a closeup (semantics). Only true macro lenses go to 1:1, and they only do so at their closest focus distance. So if you are further away from the subject than your closest focus distance, then you're probably not at 1:1. To get bigger than 1:1, you need to modify your lens somehow with either a set of extention tubes (the best method in my opinion) or another lens in front of yours, like a "macro" filter that screws on.
3) Blur can be good. I posted a thread about
Bokeh a long time ago, it may answer some of your questions here. As I said above, the closer you are, the less DOF you get for a given aperture.
4) Squirt the rose. Water is beautiful up close.
As to the overall shot, it's a beautiful rose, well captured. The quality of the window light is soft and works very well. I think the greenery and background is distracting and would have been tempted to clip it off (maybe not appropriate for a newly gifted rose on Valentine's Day) or put something behind the rose like a piece of solid colored paper.
I hope we get to see lots more soon!
