For the white balance part, did you notice the grass in the one shot with WB set as sunlight appears greener? But it's not significant. The auto wb of most camera shouldn't have any problem with sunlight, that's why it looks similar. But if you try the tungstan/indesc...(how you speel that?) the different should be obvious.
Tungstan lights are yellowish, the auto wb may not be able to compensate properly for the colours, the tungstan wb settings allows the camera to compensate for this colour cast so that the picture don't look so yellowish.
The sharpness is not affected by the wb settings.
Hmmm.. for the macro shot, the problem is with the 'blur-ness' right? One thing to note for macro shots is that camera have a minimun focusing distance even when in macro mode. if the subjects is too close to the camera, the camera will not be able to focus properly and the pic will end up blur. Another thing is that during macro mode, if the magnification is very high, shakes from your hand my interfere with the focusing, resulting in inaccurate focus. Another thing is DOF, as mentioned in the other thread. he DOF when in macro mode is very shallow, so only a very small part of the subject will be in sharp focus, so you have to becareful on tghe focusing, making sure the camera is focusing on the intended part.
For your macro shot, did you notice the pot is sharp? Perhaps its because the subject is too close or the af focused on the pot instead. And remember to set to macro mode, it allows the camera to focus at subjects that are close.
All cameras (actually its the lens) have certain limitations in macro capabilities. Thats why we have close up filters to help get bigger macros. Check out this link for some example pics. Those discussed are +4 filters. Depending on the level of magification needed, +1, +2, +4 to +10 closeup filters are easily available in the shops. Not expensive also. Around $15.
The basic function of a close up filter is to reduce the minimum focusing distance at each specific focal length. For example, if the minimum focusin distance when zoom to 3x (eg 100mm) is 60cm, with a closeup filter attached, the minimum focusing distance becomes 10cm (still at 3x zoom).
Hee hee... camera on auto and manual modes.... wah this one very stress topic.... Let's just put it this way... sometimes, there are things that you wish to do but the cannot be achieved using the auto/programmed mode. And sometimes you want to control a certain aspect of the camera...
Let's say, you want to shoot a very long exposure so that you get the streaking effect of the car's lights. You are going to need shutter piority or the fully manual modes. Or let's say you are shooting scenery and want to use a tiny aperture, you'll need to use the manual or aperture piority mode. or flash photography, when you want to balance the ambient light and light from the flash, you are likely to require to use manual mode.
Hee hee, kind of depends on situation... the programmed/auto mode in most modern camera is smart enough to handle most situations. Such as landscape and stuff... The manual mode and semi manual mode (hee he, the aperture and shutter piority) are used for a certain type of situation... say the smooth water effect? you may want to use shutter piority... For SLR and DSLR users, they are likely to use the aperture piority so that they have control over the DOF.