Using forms for web applications

I am not sure if this is the right forum for the conversation. However I am interested in knowing the community thoughts on to what extent would you use forms for creating web applications. 

My scenario is we are creating a web application that relies heavily on API's from many service providers. Essentially there is no persistence requirement in AEM except for any transient data stored before the API is called. The AEM forms is considered as presentation layer in the architecture stack. The extent of API invocation is that on the page we have few buttons and each of the button will invoke an API either to retrieve data or to submit data. Also we need to create multiple forms and there is common data to be re-used across multiple forms and required when submitting to the API. There are mid point save during the form data entry, however the data is stored in the integrated service not in AEM. This is purely because the application can be completed by other channels such as mobile app / backoff admin application which integrates to the API. 

I find it very hard and time consuming to setup the above scenario using AEM forms and evaluating other means to integrate the above web application into AEM. I would like to get your thoughts on what should I be considering in solving the above problem statement. 

Thank you and I appreciate you input.