I do agree with offering SEO as part of the service, however the price for a website will shoot up and the chance of loosing the customer is big, so saying that, standard things like alt tags, link & page title tags, h tags, bold, short description, etc. should be included in design no matter what.
The more advance SEO should be an option if the customer want to go down that road.
Related to submission to the search engines: I don't believe in that anymore. It's a scam in my point of view. Few links from others, and first should be from the designer portfolio, should get your website picked-up by the major and most important SE very quick. Lets be honest there are a handful of SE out there, the rest are just .... directories more or less.