It's 1955 and there are no missile designs available, I have Ballistic Missile tech researched, but no unit designs are available to research, nor are they available to buy from other nations. I am still new to CW and this is the farthest into the timeline I've played, so not sure if they will become available after a certain time, or this is a glitch. I looked in the manual, which stated there was no missile capability at the beginning of the Cold War. Okay, then shouldn't I have the capability after researching the techs, and at least be able to see the designs other nations have (even if they require further researching)?
It's no glitch, they will become available once you research the required tech (there are many). BG added some basic designs that are buildable "worldwide" so any country is given the chance to develope their missile program
As for the seeing the designs of other nations, the answer is no, you can't see the designes that are behind un-researched the "Era tech" so always make a priority to research "Era techs" because they are the ones that open doors to new designs and techs.