If you've played enough to have an awareness of your weakness (endgame/opening/etc) then I'd address those first. Otherwise it would be better to go through it from beginner onwards, that way ensuring nothing is missed and there's no gaps in your knowldge. I'm glad you mention tactics as it's important to augment your training with them as much as you can :)
(I'm a writer and a coach on chess.com - feel free to message me if you'd like a free coaching game :)
Best way of learning with Chess Mentor

I recently started using the chess mentor and think it's awesome, there is so much info packed in there and I find it a great way for learning in an interactive setting like that.
I'm eager to do all the opening, ending, tactics, strategies, checkmates courses etc from beginner to master a few times to let it sink in.
I'm just having some doubts about what order to learn and implement in my games.
For exmaple, stick with openings or endings first, from beginner to master, really get a grasp on it and then step over to tactics or another
OR
Do all the beginner ones, then the intermediate ones as a package so to say?
I do realize it takes a good ammount of time to go through all of them so I want to spend my time wisely.
Looking forward to all of your thoughts,
:)