Could Inform 7 games be displayed with an alternative interface, say in Flash?
Not easily. It is conceivable to write your own interpreter for Glulx or z-machine games, and to give them special features, but it would be up to you to design such an interpreter from the ground up. David Cornelson’s Textfyre company has created its own Glulx interpreter with a different approach to I/O, some version of which is likely to be made available for non-commercial use by the IF community. Information on FyreVM is available here: it would allow a Glulx game to be combined with UI components in Flash or other programming platforms.
Not easily in Flash itself, but there’s some progress towards prototypes that would allow for substantially different front ends. David Cornelson’s Textfyre company has created its own Glulx interpreter with a different approach to I/O, some version of which is likely to be made available for non-commercial use by the IF community. Information on FyreVM is available here: it would allow a Glulx game to be combined with UI components in Flash or other programming platforms. You may also be interested in the (unfinished, not yet usable) Vorple project.