You probably need to make sure that the home/profile views are enabled. They probably weren't when you first installed as you only had a canvas view. Go into manage applications: http://profileedit.myspace.com/index.cfm?fuseaction=accountSettings.applicationSettings  Change settings for the app there. 

It should not matter to your server if makeRequest supports gzip or not. Your server should only serve up gzipped content if the http header "accept-encoding" says the client supports it. So if you server acts as its meant to then when makeRequest supports gzip it should be transparent. 

When you visit the profile of the app you are meant to see just that - the app profile. From there you can find out about the app and install. Once you install you are taken to the canvas page if you have added code for it and enabled (there is a enabled checkbox that should be ticked). 

It depends on what type of app you want to create. But start by using the Javascript OpenSocial API within the MySpace container (no iframe). Most of the examples are using that method and hence the best way to get started.  If you are creating a game/app with vector animations - then use Flash of course. If you need to create something ...

The convenience method $(elementID) no longer works as the container is now missing prototype library that was there before. Just use document.getElementById(elementID) instead. To fix that sample just change the makeRequest_callback function to below:     function makeRequest_callback(data, url, ...

Great post!