1) should view.php contain html tags like survey view.php? Shouldn't a custom renderer create something like this?
Hmmm, where to start? view.php is usually the main page for your activity. Typically it might contain programming logic. You would likely use the renderer.php file for display only (an MVC type approach). Strictly speaking you only want display stuff there (perhaps using the output renderer and functions of html_writer (that includes your singlebutton, for example). For simple output you can just use $OUTPUT in the view.php (see the Page API for detail).
Forms can go into any page but you are most likely to add a form and process it in the same page. I'm not sure where that ties in to the activity you are creating.
>>Also tried to add a button using this...<<
You might want to check out the html_writer::singlebutton() method and provide a url that takes you either back to your page or to another page when the button is clicked.
Your reference to webservices is (to me anyway) obscure - are you just writing a simple activity module?
I'm not sure I'm helping but will continue to try.