So I recently started developing on the .Net Framework and I found that there is Mono, another implementation of the .Net Framework that can be run on other platforms such as Linux, Android and iOS. I have a few questions that I hope someone can answer for me.
1. Obviously, a conversion to Mono from .Net will bring some compatibility issues due to lack of libraries. Has Xamarin implemented most of the "important" libraries to Mono?
2. Is Mono on Linux the same as Mono on Android? or ie, will I new to make a lot of modifications for Mono application to run on Android?
3. Will an application developed with Mono from the beginning, transfer to .NET without any difficulties?

Thanks you for taking the time to read this.

i'm pretty sure a mono app written for linux won't work for android. it still uses activities, xml views, and an android namespace. unless you have some other program i'm not familiar with that converts it. the benefit is writing C#, not keeping it the code compatible with desktops.

Just beware even though most of the core functionality is done with mono, you will be missing a bunch of things which are windows specific and can not be added to mono, such as invoking external library functions and such.