Personalized members area / page

Hello,

I am surprised that it is so incredibly hard to create a personalized content for the user. 

For example, I want to provide API keys and basic statistics for each user after they register. The service is completely free.

For obvious reasons each members page should be personalized. My expectation was - there is a few APIs available:

1. Hook for user sign up so I can generate API keys

2. API to change a text block on one page for each specific user (based on user id)

3. API to disable the user (in case of API abuse).

Apparently that is not something that exists currently and I am wondering if there is someone who faced the same problem and managed to solve it. 

Thank you guys in advance.

Any updates on things you've tried? Working on (i think) something similar