1) where to start based on TK? (Let me remind you that there is an idea to make a clone Idel Miner)
We must start with marketing research. Who is your target audience, what niche is your product, volumes, competition, solvency, demand. Advertising budgets. Organic and inorganic traffic, etc. And it's not just words. It figures, figures, figures. Specific - who, where, when, how. If you say so seriously for a million dollars targeting.
Is there any Studio that 3 pennies can implement part or all TK Zelek?
For a penny you, the students on the knee collect. Professionals cost money. And development it's actually not the most expensive thing.
3) what will be more profitable, to go to the Studio or look for freelancers and what are the risks there?
Freelancer more profitable. Risks? Throw money to the wind.
4) Where and how to look for ads in the app? There are exchange? What's worth reading?
Google AdMob, Chartboost, APPODEAL there to dig. Gugel.