Yeah, kind of. your graphics need 2 be o.k, except u want to stick to back-end i.e: site functionality etc, and get someone else to do the graphics for you. But 'll suggest u do both.
depends on your defination of who a seb designer is.Guess you havent heard of the MCV architecture. you don't have to know a bit about graphics to be involved in web design.like i said, it depends on your defination of a web designer!