MCO isn't really junior. It's tied with DEN as the most senior 737 FO base. But.... the junior pilot in each base has been here less than a year, so "junior" is a relative term. You can likely get there before you are done with OE and almost certainly get there within a year.

Nobody really knows that answer. Prep companies will tell you that internal recs > external recs. We also know that recs from management carry more weight. I had my app in for 6 months with multiple internals, but recieved an invite 3 days after a Chief Pilot meet. YMMV.