Content and Search are two completely different beasts.
For one - you need a completely different keyword approach for each one. In search, you're looking to bring in traffic based on more or less a specific product or solution the user was actively looking for.
In content, you're trying to bring them in as they are not necessarily actively looking for an ad or a link, but you wanna have your ads present on the pages and sites they visit.
Therefore - you should research two different keyword sets. On content, you will usually have a larger negative keyword list, for example. Having it in its own campaign also makes sense from a management point of view. You can give each campaign its own ad-scheduling and budget. Budgeting a search campaign can also be very different than budgeting a content campaign in the same niche, for the same product.
For both search and content campaigns however; always set up smaller, tight adgroups with closely related keywords (if doing keyword-based content). For placement-content, break it up into several site adgroups based on site themes and demographics.
And lastly...yes, your CTR will be fucked in the asshole if you mix it all into one campaign.
