Notifications can be sent?

Hi,

I'll try and help as best I can. I can't promise that this module offers the best way to achieve your goals, but I don't know of anything better.

The event creator can set a limit on how many people can sign up

webform can handle that.

Custom fields for each node's forms (I probably need around 15 different reusable registration form types)

That fits in nicely with the webform philosophy - each registration form can be a different node of the webform content type. What can be frustrating is that there's no way (that I know of) to share components between webforms (eg. on every form the personal information will consist of three textfields, for name, email address, and phone number) which can lead to annoyingly repetitive creation of forms.

Instant email confirmation sent to the user’s email account

webform can handle that

An email reminder to be automatically sent out 24 hours before the event

I'm not sure what the best way to do that would be. I wonder if you couldn't do something using rules; but there may very well be a contrib module that offers precisely this functionality. If it came to it, it wouldn't be particularly difficult just to do a custom cron run that sends out appropriate notifications.

Ideally I'd like to set up a text message system as well.

I've never used it, but you might want to look at using a messaging API such as Notifications.

The ability for the event creator to look at a list of everyone who has signed up

webform can handle that

Ideally this would be exportable into a spreadsheet.

webform can handle that

Let me know if you have any more Qs.

HTH

Glad it was helpful! Good job on getting the SMS sorted - out of interest, how come you needed Notifications _and_ SMS Framework? (I've not used either before.)