I have bundled products with dynamic skus and would like to be able to add them to orders through the admin. The bundled base products do not show when using the Add Product search. Is this possible on a newer version or should it be possible on CE 1.4.
Personally I don't have a Magento 1.4 instance running anymore, since this version is very outdated. So I checked your question on a Magento 220.127.116.11 instance, which is the latest version.
When creating a new order from the backend, you have to select the products you want to add to the order. For a bundled product you get a link "Configure" behind the product name. When clicking that link, you get a popover in which you can select the options you want to be added to the bundled product. The same goes for configurable products and grouped products.
This is Magento 18.104.22.168, but it should be really easy to check this for other Magento versions as well.