I understand how you feel (I think) to some extent, since there were (and are) things I wish I’m doing less of. Below is my personal endeavour in working through them; I hope some of them resonate with you.
First, I concur with you that this site is a treasure; coming to it, reading it, and reflecting on it, changed my mind significantly (I hope). I believe Lal created this site to provide resources for us to reach at least the sotapanna stage, so that was one of the first things I studied.
To reach the sotapanna stage, the only defilement to be removed is wrong view (micca ditthi), starting with the 10 types of micca ditthi. So, that’s what I did, i.e. studying and reflecting on the 10 types of micca ditthi.
A little digression here: I can’t tell you how eye-opening just this bit of information was. I used to be told what it took to be a sotapanna, such as: your concentration must be so good that when you sit in meditation, if someone puts your favorite dish to your nose, you won’t smell it; only that kind of concentration can lead to insight. I couldn’t tell you how discouraging that was, since I knew my concentration!
You asked about the most useful practice to do should you end up a miser. I would start with meditating on the 10 types of micca ditthi to get started on the mundane path, contemplating on why having them lead to serious consequences.
Specifically, wrong view #4 about kamma / kamma vipaka on covers a number of other ones. I can honestly say that I am fully convinced of this point now, and it makes the mind feel so much lighter. If things do not happen randomly, that they have causes, then there is always hope. You are also making this point of kamma in your post, so you’ve got a good start.
#6 on the list about para loka and the world of the gandhabba also brought joy to the heart. This was new to me (and I had been studying Buddhism for 30 years prior!). Studying it, seeing how it explains rebirth, was again eye-opening and absolutely convincing, and there was no longer doubt about rebirth, which was another milestone for me.
I did some deep diving on this point about the nature of the gandhabba (or manomaya kaya) with the hadaya vatthu and pasada rupā and so on. Learning the details of the mind again brings lightness to me.
As I began to see incremental BENEFITS (however little), I felt motivated to keep going (and doing better with the 5 precepts in the meantime). Now, the benefits of learning dhamma outweighs those of some forms of sensual pleasures for me — the kinds of pleasures I once held dear; and I gained confidence that the others will fade with time.
That was how my personal journey started with puredhamma.net. Here’s wishing you will be less burdened.