1. For normal daylight exposures of at least 1/125th sec., you don't need mirror lock up.
2. Optimal apertures for sharpness (regardless of the lens) are f5.6 - f 11.
3. I've never seen a digital image (except for one that is intentionally soft focus) that didn't benefit from the use of Unsharp Mask. But always do that LAST, after your image is scaled to it's target size.
And the FIRST thing to do with any image taken into Photoshop is to optimize it, whether in RAW or jpg. Optimizing means, first and foremost, adjusting the Histogram - black slider first (this one is absolute), then white point (subjective), and if needed, a mid-tones adjustment.
Never adjust brightness, contrast, color or anything else until that Histogram is right.
Contact me if you have questions about this. I'm about to write a new tutorial on it for my site and would appreciate any questions.