Have half of BTC at hand. Want to find a way for better investment rotation to be done. So far invented such a scheme. The whole amount to be exchanged for any local currency. Surplus since last investment to be converted back to BTC. Remaining - initial investment - to be spent on daily needs. Converted BTC to be put back into wallet. Two points of interest here.
First: Does this way of turnover looks reasonable at all?
Second: How to make sure I use "clean" BTC from source of exchange?