Good questions! If you consider SEO campaign, the contents of pages must be different in some way. So, I do think it is better to embed the content directly into pages! Because these 2 would be the same thing if you consider SEO factor, especially for the hard competitive keywords.
1. The contents of your CSV file may be indexed, but you can prevent this with a line in your robots.txt file.
2. Whether its better to embed the content or pull it in with a script depends on what the script does and what the resultant page contains. Will the script put in good page titles and compelling meta descrption tags, a variety of page headers etc. In general from an SEO point of view you need to have a well optimized page and that is seldom possible by using a script.