You can go to https://store.xamarin.com, login, go to your account page, and then download products individually - so just download Xamarin Studio and Xamarin.Android for Windows, install those and you should be fine.
Go to https://store.xamarin.com, login, click on your name in the upper-right corner, select "Install" from the drop-down menu, and then you'll see each of our products. In the Xamarin Studio section, select the version you want.
If you go to the URL I mention in my post above, you can download the individual installers. That might work better for you.
The iPhone Simulator has a menu item to change the zoom level.
@SurendarModugu You'll want to switch away from mdtool and use xbuild instead:
xbuild /p:Configuration=AppStore /p:Platform=iPhone /target:Build MyProject.sln
With xbuild, you can even do stuff like this if you don't normally want the build to produce an IPA (i.e. you don't want to set the BuildIpa property in the .csproj):
xbuild /p:Configuration=AppStore /p:Platform=iPhone /p:BuildIpa=true /target:Build MyProject.sln