I've never really bothered with tanking classes in this game. I prefer DPS or Heals, even though I'm only average at it. I have a Mara in the 50s but I like the aesthetic of the Jugg and want to maybe try the tank spec. Should I bother with defensive mods/relics/implants, etc., while leveling or focus more on damage to kill mobs quicker?

When you are leveling I would suggest using dps gear, maybe use a shield. Leveling as a pure tank..a bit slow in my experience.