Yes you can, to some extent by wrapping it in function call. What I typically do is to have a utility function which I can call upon whenever required.

Something like this:

popOpen: function (url, target, height, width) {
        var newWindow, args = "";
        args += "height=" + height + ",width=" + width;
        args += "dependent=yes,scrollbars=yes,resizable=yes";
        newWindow = open(url, target, args);
        newWindow.focus();
        return newWindow;
}

You can further reduce the parameters by making it an object like:

popOpen: function (params) {
        var newWindow, args = "";
        args += "height=" + params.height + ",width=" + params.width;
        args += "dependent=yes,scrollbars=yes,resizable=yes";
        newWindow = open(params.url, params.target, params.args);
        newWindow.focus();
        return newWindow;
}

And you can call it like this:

var param = { url: '...', height: '...', width: '...' };
popOpen(param);

Or,

var param = new Object;
param.url = '...';
param.height = '...';
popOpen(param);

The simple answer is yes. But make it a function that calculates those values when called. In other words:

let helpDimensions=function (w,h,l,t) {
return "width="+(w||findWidth())+", height="+h||findHeight()+", left="+(l||findLeft())+", top="+(t||findTop());
}
//this lets you pass a width, height, left, and top to override the calculated dimensions.
/*you will need to establish a findWidth(), findHeight(), findLeft(), and findTop functions or include them inline like:
return "width="+window.innerWidth*0.8+", height="+window.innerHeight*0.8+", left="0.1*window.innerWidth+", top="+window.innerHeight*0.1;
*/

/*then just perform function call like this:
window.open(url, title, helpDimensions()); to calculate the correct dimensions each time
*/

Also, establish a click handler on an element like this:

$("#someelement").on("click", function (e) {
e.preventDefault();
window.open("test.html","test", helpDimensions());
});

using jquery to set the onClick attribute of an existing element is a bad idea.
Also make sure that all of this is enclosed in an Immediate Invoked Injection Function or IIIF like this:

$(function () {
//define your helpDimensions function to calculate dimensions dynamically
//define your click event handler
});

//this ensures that it is not called until everything is loaded.

Hope this helps.
Here’s a great website for calculating dimensions and working with the window reference object to ensure that your content goes into the correct window (which can be reused if needed):

Center a new popup window even on dualscreen with javascript

function PopupCenter(url, title, w, h) { // Fixes dual-screen position Most browsers Firefox var dualS...

false will be typecast to a string, which will be "false".

Set the value to the URLFOR for the Event View:

<apex:outputLink value="/{!list.id}/e?retURL={!URLFOR($Action.Event.View, Event.id)}">click me</apex:outPutLink>

Here is a working VF page using contact as an example in case the above does not function as expected

<apex:page standardController="Contact">

<apex:outputLink value="/{!contact.id}/e?retURL={!URLFOR($Action.Account.View, contact.Accountid)}">click me</apex:outPutLink>

</apex:page>

To add parameters to the URL add parameters like:

[param1="value1", param2="value2"]

After the ID like:

URLFOR($Action.Account.View, contact.Accountid,[param1="value1", param2="value2"])

There are a number of issues here. First, of all, the values you use in your example (top=500,left=2000,height=600,width=400) are likely to put at least part of the window off screen. This will be automatically corrected by the browser. As MDN notes:

Requested position (top, left), and requested dimension (width, height) values in windowFeatures will be corrected if any of such requested value does not allow the entire browser popup to be rendered within the work area for applications of the user's operating system. In other words, no part of the new popup can be initially positioned offscreen.

Secondly, in the code where you are checking the position, you're actually reporting the main window's position, not the popup's. Instead of:

console.log("top=" + window.screenY + ", left=" + window.screenX);

That should be:

console.log("top=" + popwin.screenY + ", left=" + popwin.screenX);

This example correctly positions and reports the position of a popup window:

<!DOCTYPE html>
<head>
  <script type="text/javascript">
    function popup() {
      const popwin = window.open(
        "", 
        "", 
        "top=300,left=300,height=40,width=400,titlebar=no,popup=yes"
      );  
      popwin.document.write(`top=${popwin.screenY}, left=${popwin.screenX}`);
    }   
    popup();
  </script>
</head>
<body>
</body>
</html>

Lastly, concerning the address bar: it is in most modern browsers no longer possible to open a popup window without displaying the address bar, for security reasons. See more info in this answer.

In conclusion, there are better alternatives than using popups. They annoy users, and are routinely blocked by browsers. Depending on your use case, you could use something like a dialog element.

According to the API specifications of Window.open(), you specify the window features in the 3rd parameter. Therefore, you need to set the 2nd parameter, otherwise whatever you specify in the 2nd parameter will be interpreted as the window name.

I don't know much about asp.net, but looks like you have a javascript problem. Isn't document.getElementById("hlUser") an <a> element? It has no value attribute.

If you want to get the text element inside the <a> you could query the text property, or innerHTML.

<a id="hlUser">somevalue</a>

document.getElementById('hlUser').text will return somevalue

UPDATE: Having that <a> inside a repeater makes it impossible to know with confidence any id attribute inside it beforehand. I'd reccomend passing the <a> element, or this.text itself , or even the value using the same server-side script to the function.

UPDATE 2: I see this question might be a duplicate of How do I pass a variable using window.open()?