sometimes I struggle with .install files

It might be me (almost certainly) but after upgrading to 4.7 a few weeks ago I have run into a few niggles with the automatic installation of database stuff. In some cases (ecommerce over a 4.6 version and tinymce after I had deleted the tables! (see below)) I have had to run a little script as per:

include_once('modules/xyzmodule/xyzmodule.install');
xyzmodule_install();

For a module that I have been writing (TO DO I will post something on that later and edit in a link here) I have found (following someone else's tip) that I had to delete the tables I had created and delete the relevant record from the system table.

This all seems a bit too non-foolproof.