A module with an install file gets run at install, for an example if you install/enable a module with one hook_install
and three hook_update_
all of those will be ran, and the database will be set toonly the last hook_update_
so if you where to add a new hook_update_hook_install
you could run update.php which would run that hook functionwill be ran.
The best way to do what you want to do is create a module like you want, with a empty hook_install
then just keep adding hook_update_
functions as you need to do more stuff, then when you are done run update.php to run all the hooks.
It may also be a good idea to separate the types of stuff you want to do into groups (like create new items, and add them to the database, then another hook could be delete x and y, and another could be rename a and b) and add them as hook_update_
so for example if you need to run something more then once for an example or maybe down the road, you could just call update.php and run that specific hook_update_
function (if you for example wanted to run delete x and y more then once, you can).