I’d like to use FTC http://www.bkeeney.com/formatted-text-control/ and compile apps using the source code, and then deliver the compiled binary apps which would include FTC features to my end users. I’m not sure if this would be allowed under your license. It sounds like every end user would need to buy a copy of your license, which is not tenable for my interests (delivering a $3 app on the Mac App Store).
No, the license is good per developer. So if you did a project using FTC for a client and handed the source over to them so they could make changes, the client needs to purchase a license. Same as if you were using plugins.
So if only one developer (me) has the source code, but compiles an app for a million users (who never get the source code) only the one developer license is needed.