If you really feel that the AF needs improvement, you must be shooting with the Oly 14-42mm. I have the EP1 with the Lumix kit lenses and the Oly 17mm and find AF to be just fine (camera body and all lenses at F/W 1.1). In any case, it seems that the general consensus to improve AF performance is to have the AEL/AFL button set to AF only and have the shutter set the exposure and actuation. This can be accomplished by going to the Menu/gear/Button/Dial/AEL/AFL/S-AF/select mode 3.
Some of the settings I've chosen are:
AUTO WB tuning = A -1 and G +1. This removes some of the magenta casting the camera produces when photographing white objects in the shade. I find the Shadow/Cloudy presets to be way too warm. I've also set the Custom WB to K5400. That is a slight offset from the Daylight preset (set internally to K5300), which is just a tad bit warmer. Daylight can be too much on the cool side sometimes.
I've set My Mode 1 to high ISO (min 800); Matrix metering; Natural color mode with contrast -1, saturation 0 and sharpness +1; Noise Filter High (you might get away with Standard if shooting in not so dim conditions).
I've set My Mode 2 to low ISO (100). Unfortunately, the EP1 will not go below 200 in AUTO ISO mode (don't ask me why). I personally find ISO 200 to be noisier than I like. The problem is, when you set the camera to ISO 100, it tends to over expose. So, here are my settings: Center Weight metering; Natural color mode with contrast -2, saturation -1 and sharpness +1; Noise filter LOW (or even OFF since at ISO 100 noise is very much under control); Exposure -0.3 to compensate for the camera's over exposure at this ISO setting. Some times I could do with -0.7 but the problem is, once you save your configuration to one of those two My Modes, you can not change it on the fly. So, I prefer to keep it at -0.3.
Then, I set the My Mode 2 as default since I shoot more in good light.
Lastly, you must set the Fn button to My Mode so you can toggle between the camera's normal settings you've selected and the My Mode (2 in my case since it's the default) by pressing and holding it before shooting. It would be nice if we did not have to hold it down as with the AEL/AFL button. Press it once to set and again to exit, which is my preference but many people dislike that because if you forget to press the second time, your exposure may be way off once you point the camera to a different area.
As you can see, I have the Noise Filter set to ON most of the time. The reason is twofold. 1) the EP1 is noisy; and 2) the NF is not nearly as intrusive as it is on the E510/520 (particularly the E520). So, you hardly loose any resolution (IMO) by having it set to LOW or even STD and the images will look much cleaner that way.
I've changed the VIVID settings to tone it down a bit in case I want the images to look a little punchier.
The Art filters are nice, particularly the B&W and Pop Art. They certainly produce interesting results. However, it takes time for the camera to record the image, so you can not shoot very quickly.
I also have the AF point set to center, no face detection. The resolution I have it as LF. I did not find any difference in IQ between LF and LSF. Just in file size, which gets much larger.
I always have the Histogram on display in the LCD and Shadow/Highlight turned ON so I can see how the image is exposed and make any adjustments that may be needed in case it's over or under exposed.
I think that covers most of it.