Bitcoin is the PERFECT tool? Surely a coin like XMR, or even a Zerocin based protocol would be a better choice, mixing or not - BTC can of course be traced back through the blockchain more than you think.

Also, what do you mean by "nobody will trade you if you will use mixers and service like that" - If I need to buy BTC, I do not check the blockchain to see whether it has come from a single or multi input, why would anyone do this? Look at that money in your pockets, do you think only law abiding people have used and handled that only, maybe even those coins have been mixed and tumbled with others to dilute and create level of anonymity ?