Firstly, I want to say I think you have made the right decision.
But, I hope we (or me!) have not been responsibe for that decision. All I wanted to do was to paint a clear picture of what billies are like when they are entire. All to often, people get them, find they cannot cope, and then what? Unless they are well bred billies, really good quality, they are hard to sell or even give away .......and thats not fair on the billy goat. Its not his fault is it!!!
In all honesty, do like you say, enjoy your nanny goats, by all means let them kid, and then you have milk.
Do go and visit a stud with an entire billy goat ....ask questions........I am pretty sure you will come away knowing you have made the right choice in not keeping one.