I have not yet published a program in the Windows Store. I have not yet developed any programmes for the general public. I'm the same as you. I mostly develop programs for fun and to realise my own ideas, which are sometimes quite specific.

I wouldn't worry too much about open source. You certainly have to make a few considerations regarding the licence. As far as the code is concerned, I can understand your reservations. Sometimes I'm also a bit of a mess when it comes to testing and understanding other people's code. But with a little documentation and tidying up, it usually works.

In summation, progress continues despite ongoing competition from my "day job" and household/family obligations.

I know that only too well. I basically have the same "problem". I usually don't manage more than two hours at a time, if that. As soon as I'm really into it, I have to stop again... or it's too late...

is a fun project that I could revise and extend endlessly.

I feel the same way. One idea follows another once I'm in the process... Unfortunately, not everything makes sense and can be realised in a reasonable amount of time.

I'm curious to see how you will continue...