Free version of Premier Rush and 3 Exports

I was just hoping to clarify - I'm a long term user of Lightroom and started to get more involved in video. I'm an Apple guy, so naturally I tried using imovie but it appears getting content from Lightroom to iMovie is pretty clumsy. Then I came across Premiere Rush and thought I'd try it out. I like the app, but I seem to have 2 major issues:

1- Again, I can't seem to find access to my adjusted Lightroom images (but ironically it does see my Apple Camera roll images ... just like iMovie). Am I missing something or is it true that an Adobe product can not see Adobe Lightroom?

2- 3 exports - I had assumed the use of the word "export" was referring to a special method of easily sharing the video, but that one could save unlimited videos and simply send the old fashion way. And since the product was called Premiere Rush and not Trial Rush, I assumed this was not just a Trial Version. Can someone clarify if I am understanding that accurately?

If I'm not missing anything above, then my next question would be, why leave iMovie if I'm not gaining any ease of access to my Lightroom images, and its going to double my monthly cost? What is the benefit of Rush over iMovie?

Thank you!