It's a nice friendly looking website. It's hard to explain how I feel about the design. I prefer websites having a nice corporate feel to it but your website doesn't have that but at the same time it just has a certain friendliness to it.
We always put our link at the bottom of our clients websites. If they want to have it removed they can but most of them are happy to have it there. If you do a good job then they are likely to tell their friends which is also free advertising.
You really need to test your websites on a computer too. As you said the colours look slightly different on a laptop than they do on a computer. If you buy a new keyboard and mouse for your laptop then I can't see why there would be any more problems.
Your whole page is in a container called mainbody by the looks of it but you have no css giving this class any attributes. Try adding this to your css:
#mainbody {margin:0 auto;} I always use an auto margin to centre align containers in ff.