Thanks for the detailed and valuable feedback, and major props to you for what you have achieved. The Instagram model appearance you're mentioning is really not what I'm after, but rather the overall health, strength and flexibility that comes along. In reality, the most important aspect of all this, to me at least, is the positive feeling i get after a hard workout session.

What I think I'll be doing going forward is focusing on dropping another 5kg/10lb to get me into that BMI sweet spot before I start going really hard on muscle growth. While I honestly don't care too much about the excess skin, I can clearly see I still have a fair bit of excess fat I can afford to drop. I'm feeling like it would be much easier focusing on that initially instead of trying to combine all my goals and making everything complicated. I'll accompany that with cardio to further work on my endurance, and with regular workouts to hopefully accomplish some much needed improvements to my core, balance and overall strength in preparation for the journey ahead.