1. It really depends on what you mean by "big". In general, Construct 2 doesn't limit the scope of games you can create, within reason. It's all really a matter of how much effort you're willing to put in. If we're being honest, a lot of users have a poorly calibrated sense of how much effort is required to pull certain things off.
2. It can be done, and again, Construct 2 won't be the limiting factor when it comes to scope. I'd suggest searching through the tutorials section for ideas on how to do this.
3. You're a beginner, these are beginner questions, I'd say yes.
Also, welcome to forums, it's good to have you!