I'm not sure if we agree or not. I'm not at all after the classic sourdough taste, and am not really interested in keeping a friend. I buy bulk dried yeast and always use yesterdays dough as a starter, do a slow ferment in the fridge, or keep a fresh sponge fermenting for a day before I actually make bread. lots of fermentation really does develop a richer flavor.
if I do want to grow a friend you suggest I turn my culture over often to stop it getting too funky, and use proofing chamber to get rapid yeast development when actually baking?
My understanding is that it really doesn't matter where you get the culture from. It takes a couple of weeks to get a starter started so if you want to get into sourdough baking I'd recommend just buying one if you can get one from anywhere else.
(I created my own mostly out of curiosity, it's fun, but it takes a couple of weeks)
I often hear about how for example the sourdough bread in San Francisco is special and that this has something to do with the culture. I don't think this is the case. My understanding is that you tweak the taste using temperature and proofing time (and flour mix, obviously). Personally I don't want my bread to be sour, so I generally feed the culture frequently and proof the dough at around 27C. If you lower the temperature and proof for longer you get a more sour tasting bread.
If you just want to make a tastier bread then simply using very small amounts of baker's yeast and a long proofing time (at low temperature) will get you very far. It takes time to develop the flavours and the main reason the store bought bread is so bad is simply that it's produced so quickly.
Oh and I can also recommend the dutch oven trick, with sourdough or not, it really is a very simple way to make great bread at home.