It cant, tor is only resonable secure because of its sheer amount of users.
Not to mention that every exitnode can sniff traffic and tor itself makes more sense for internal onion browsing and not as a bridge to the www.
then u need a browserbundle which is perfectly tight at security. And tons of tordir and bridgeservers, middlenodes etc.
And the legal problems... makes sense to earn 20 cent a day and risk jail for that.
And if u think you can make that better than a million funded and 10 year old project with a shitton of security experts you must be totally insane.