No, it was NEVER intended to be a fighter, but I think its air-to-air capabilities were both over-stated in the early days and over-expected.
Maybe. Maybe not. Depends on who you planned to fight. How many nations are fielding 4+ generation fighters? Against 3rd and 4th gen fighters, F-35 is damn good. Indeed, how many currently fielded Falcons, Gripens, Rafales and Typhoons have helmet mounted sighting/cuing systems and off bore sight weapons? Heck, the F-15C, still considered a front-line air superiority fighter, still uses steam gauges rather than multi purpose flat screens.