I'm not an expert photographer, barely an amatuer even, but I know that perceptions of sharpness are completely different from one person to the next. Grainy-ness (is that a word) could actually be a good thing and caused by several factors.
Please post an example photo of what you think is un-sharp and or grainy, with exif data, and lets us take a look at it.
Constructive criticism makes everyone a better photographer, in my opinion.