Yes, lots of glass and transparency will slow your render to a crawl with lots of lights. Try changing your render settings to the default settings for the time being and see how fast it speeds up. In the skylab, also make sure "soft shadows" is not selected below the sun control (see attached pic). If that is checked, even if you are not on premium render settings it will render like it is, and that can take a very, very, very long time, especially with transparent materials.