closed as too broad by PolyGeo♦ Dec 19 '15 at 3:30
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
I've also used custom projections (planets/asteroids) that Esri doesn't have Well-Known ID's (WKID) for, but using the Well-Known Text (WKT) strings has worked just fine.
However, if you take this approach you will have to take into account your current knowledge of Dojo and AMD as this could impact how much effort you have to put into development. ESRI has a lot of example code and widgets to help you get up and running quickly though.