Raw images from a camera never are "super" crisp - the nature of the "film" they use means that additional post processing needs to be done to bring back that sharpness you are seeking... Thing is i dont know how your pics are coming out or what level you are expecting so i cant really say 100% that everything is fine.  My encounter with the kit lens was a good one, i had no issues with it - you get what you pay for really and considering it is about the £60 range then i think it was a fantastic lens.

As for your next lens the 70-300 is a decent lens - i have the first version of it (the one designed for film without any coatings) and it takes some nice shots as long as i have a lens hood on it (glare/flare is a bit of a problem with this one)- considering they are selling on ebay (my version that is) for around the £70-80 i think it is worth keeping just as a backup (i recently got the 70-200mm 2.8).  If you are just starting out and are on a budget then getting these "budget" lenses is a good step to finding out what you like to shoot and how you use your camera - if i am not mistaken then the 70-300 is also a "macro" lens so you can get some fairly decent closeup shots with it and thus see if you like macro photography enough to invest in a specialist lens.

The other thing to consider is that if you want extremely crisp shots then you will eventually have to use fixed focal length (prime) lenses, and if you dont mind walking backwards and forwards for your "zoom" then i would thoroughly reccomend the Canon EF 50mm f/1.8 - it is a "must have" lens at £60 (i have two... long story ;))

"In every colour, there's the light.
In every stone sleeps a crystal.
Remember the Shaman, when he used to say:
Man is the dream of the Dolphin"

Rich Meadows Photography