Well, about the rotating, just move the pivot (press INS to move the pivot and INS again to return to object) of the object/components you want to rotate and move it to the point you want to rotate it around...

Snapping... Well, there's Grid snapping, Point snapping and Curve snapping (or at least these are the only ones I know of)... Press and hold X, V or C (in the order mentioned above) to use them, and drag (just clicking isn't enough) with MMB to where you want to snap to...

Creating curves... Hmm... There are more ways to do this... You can create primitives (circles and so on) to create the curve you want and then intersecting them and deleting the obsolete parts and combining the rest into one curve... Probably a simpler way would be to just draw the curve using the CV or EP curve tool, and if you need a curve that is straight in someplaces and curved in others, you can change that in the tool options (when you use the tool is becomes availible just beneath the standard tool icons (move, rotate...) and you just double click the icon to open the options... BUT this will create a new curve (I think), but then you just use the Curve snap to start off where the last curve ended, and then in the end combine the curves into one...

Navigating is quite simple, you hold down the ALT key and then use the mouse buttons the zoom, pan and so on (can't remember which does what), and F focuses on the selected object/components if you get lost...


Hope this clears out a few things...

Oh, BTW, and keys and so on are for Windows, don't know anything about Mac...