Alexander,
You can only install Smart Home into MyEclipse with the Smart Home Update site http://download.eclipse.org/smarthome/updates-release/0.8.0 and using the Help > Install from Site item.
Unfortunately, the provided update site is incomplete and the installation kept failing at different levels due to bundles that are missing from the update site. I did add a number of these manually, but the installation simply failed at the next unavailable bundle.
I would approach the SmartHome team and ask them for an update site that would allow installation into MyEclipse, or even a regular Eclipse distribution like the Eclipse for Java EE developers (I tried there too and the installation fails in similar ways). It’s possible that there is an additional update site with all the required binaries that hasn’t been referenced. I also suspect that this may be the reason why the provide a binary IDE-style installers making them easier to use.
We can investigate further, but I’m afraid the installation will not be straightforward.