Global configuration for a block type is something I am interested in. Was there a solution to this?
What are the usual solutions for global configuration for a block type?

I don't believe it's possible to hook into this page (although it's a great idea).

The two ways I've handled global block configuration are:

1) Create global config constants that the user must put into their config/site.php file. This is a very easy but only works if you have a couple of settings and don't need to change them often.

2) Create a dashboard page where the options can be displayed and changed. You can either save the config options to a database table that you create in your package, or you can just save them as concrete5 config options, as described here:
http://www.concrete5.org/documentation/developers/system/config-pre...

Thanks, it looks like the C5 Config options is a solution that will suit my purposes.