Exploring wordpress as a web application solution

Hello,

I’m exploring the option of using WordPress for building a web application and I could need any kind of advice.

My needs are the following:
1. I will need to have custom forms that will save data on custom tables.(2-pages form with 1-M data relationship)
2. Retrieve those data in preview/printing mode.
3. Create a rating system for custom posts and users (When u like a post the writer gets points based on rating grade.)
4. Present data based highest rated users.

From what I have read, I can build my own tables but I can’t find how to bind a custom form to those tables.

I’ve seen that I can create a custom form but what happens if I need to have 2-page form with 1-M relationship between data?

Any references or help will be appreciated.

Thank you in advance.