Huzzah, my idea got selected!
, this is an awesome analysis. At the moment I honestly can't think of a single thing I'd add or change.
Strikes me as a bit strange that one of the prime deciding factors upon which the decision whether or not to contact a new race is if they possess a particular type of propulsion. After all, it is merely a technological achievement, and says nothing about the species as a whole.
I don't think warp-capability is really the deciding factor. I think it's 'has the target species gained awareness of aliens?/is them gaining that knowledge inevitable?'. Warp capability usually coincides with positive answers to these questions so it's commonly used as a shorthand for that. But if they somehow manage to stumble into you using just STL travel or FTL communications or even STL communications, you'll initiate First Contact even if they don't have warp travel. Also, if you somehow reveal your presence to them and you are not able to 'erase' that knowledge (say, your ship crash lands right in front of the eyes of the entire planet) you'll have to initiate First contact even if they are still stuck with just chemical rockets!
As for the case of an advanced civilization that hasn't entered space - I don't think the Federation ever takes an 'agressive' stance in FC situations; it will always wait for the other side to enter the interstellar arena by it's own will. Otherwise, it would be medling in their natural development and thus against the PD, and that overrides whether they have something that could be useful for the Federation.
I'm not totally sure where to take this writeup, that said. I have a post more or less done in Notepad about "After First Contact", or should I junk that and go directly to cases where First Contact is made with someone who's had FTL travel for a while?
Don't junk it! The more the merrier.