Hi Chris,
That sounds about right to me. As long as the relative url is the same structure on both it should mostly work correctly on the dev machine, but be careful as some links in the content may have fully qualified urls in the content and its possible you'd click a link and end up back on production without noticing it.
Currently in mojoPortal the editor is configured to use releative urls for links internal to the site, and these are more portable, but some features like the blog must use fully qualified urls for links and images otherwise the links and images won't be correct in the outbound feeds. Some previous versions of mojoPortal may have used fully qualified urls more generally so depending on your upgrade history its ossible you have some fully qualified url used in your content.
There are some folders which may be best not to copy.
Sites/[SiteID]/systemfiles
Sites/[SiteID]/index
are probably ones I would leave out. After the site is up on the dev machine, do a search and it will rebuild the search index.
Hope it helps,
Joe