Thanks for the explanations. So if I create the rectangle and immediately switch to the select tool yes I get to see its properties and change them. It did not occur to me to try the selector because the object seemed to have disappeared as soon as I clicked elsewhere. I'll be damned if I know why it was white: I have _viewed_ some SVG documents in Inkscape before but this is my first stab at creating one.
In the status bar I would suggest not using F and S but spelling out Fill and Stroke in full: there is enough space for that and if you are a newcomer and both F and S say "N/A" it is not obvious what they refer to. Besides it seems weird for the stroke to be N/A: I can understand having no fill but how can an object have neither fill nor stroke yet still somehow exist? As per your own message, shouldn't the stroke have been white or transparent and not N/A? White is definitely a color and in most editing tools transparent _is_ a color, too, albeit obviously a peculiar one.
Inkscape is not a viewer. Its primary function is editing. Therefore, plain arrow keys are reserved for the most basic editing action:
OK.
-- O.L.