Hello ,
I don't understend why users need 5 -15 minutes to add email , phone number .
hotspot must work in this way . Users try to access a site . users are redirected to login page where insert login details (email , phone number), after are redirected to original page . we can setup a time 24 hours - users can access insternet without be redirected every time when access a page.
How many users can use same credentials . Some users come with family and need access on laptop, smartphone , tablet etc. if is not to expensive for you we can send credential SMS . when an user make check in at hotel receive a SMS with those credentials . this require a SMS gateway (usb dongle with SIM inside or a third party SMS gateway ) .I can make a page for adding users and billing plan (price , speed , volume/traffic ).
Best regards ,
Octavian