Hi paul,
Thank you for contacting us!
Let me answer your enquiries:
1. Can you share a code example of this case, because I was unable to reproduce this case.Also check the console for errors.
2. You can use the footerTemplate property of the smart-window to overwrite the default one and create custom one. I
have prepared a little code example on how to achieve this. I used the event ‘open’ of the smart-card-view.
More about the footerTemplate you can check in the smart-window API here :https://www.htmlelements.com/docs/window-api/
//In you JS File:

window.onload = function ( ){
    const cardview = document.querySelector('smart-card-view');
        cardview.addEventListener('open', function (event) {
        const window = document.querySelector('smart-window')
        window.footerTemplate = 'footerTemplate'
        let id = parseFloat(window.label[0])
        let deleteBtn= document.getElementById('deleteButton')
        deleteBtn.addEventListener('click', () =>{
          window.close()
          removeRecord(id)
        })
    });
    function removeRecord(id){
        cardview.removeRecord(id-1)
      }
}

And in your HTML file:

    <smart-card-view id="cardView"></smart-card-view>
    <template id='footerTemplate'>
        <smart-button id ='deleteButton'> Delete</smart-button>
      </template>

Note that I have used this demo for base : https://www.htmlelements.com/demos/cardview/deferred-scroll/
3.This on will be similar to the previous one:
//In your JS file:

window.onload = function ( ){
    const cardview = document.querySelector('smart-card-view');
        cardview.addEventListener('open', function (event) {
        const window = document.querySelector('smart-window')
        let okBtn = window.querySelector('.ok .smart-button')
            console.log(okBtn)
        okBtn.addEventListener('click', function (){
            alert(okBtn.textContent)
        })
    })
}

Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team
https://www.htmlelements.com/