I think your thoughts on micro-commitments is a great idea. It allows people that may feel ‘beyond the learning years’ to be more comfortable with bite sized pieces of Welsh to learn.
I am Canadian and one thing that we do is have any mandatory information on labelling (warnings, directions for use etc) in both english and french. That way it becomes part of everyday life in an unobtrusive way but it reinforces the bilinguality of the country. I don’t know if the labelling is the same in Wales, but it is a handy way to pick up vocabulary.
I think that it is very exciting that the Welsh government is looking at this. I wish that I was there.