Pff that's a difficult one with the resistance. It makes me think of when you're tired some people say 'then sleep, your body knows how much sleep it needs.' well NO, not at all. I can sleep so long and then I'll feel even more horrible. Think that has more to do with depressed feelings or not wanting to be present anymore... Anyway. And when you are tired, when to chose between exercising and doing stuff or really just rest? It's difficult to find that balance. I sometimes notice that I'm extremely tired because I'm really sad and am pushing that away...
I don't know how it works with the inner child either. Maybe I'm to impatient, I want a 'quick fix' for feeling better instantly. But you say the things you do for your inner child work quickly. Did they work quickly after doing them for a while or instantly? Maybe it's my negative punishing voice that comes up with the resistance. I have a hard time with selfcompassion too etc.
Being able to know when resistance isn't right for you: I think you'll be able to do that if you're grounded and know yourself better and can listen to your intuition and your feelings? I'm not that far yet... I don't know what I feel most of the times and am in my child role most of the times, not grounded and living in the past. and the worst thing is that I don't even see it myself often: it's so normal. But I'm getting there. (thinking positively haha)