All below is possible in MSIE 5.0 and higher versions of Microsoft browser (part of it works even in Mozilla and Opera)

1) Use behaviors (only Microsoft) example:
<input type="text" value="" style="behavior:url(date.htc)">

Source for date.htc:
<PUBLIC:COMPONENT lightWeight="true">

<PUBLIC:ATTACH EVENT="onblur" ONEVENT="checkN()"/>
<PUBLIC:ATTACH EVENT="onfocus" ONEVENT="doFocus()"/>
</PUBLIC:COMPONENT>

<SCRIPT LANGUAGE="JScript">
function doFocus(){
   element.select()
}
function checkN(){
if (element.value.length==0) return;
r=/^\d{2,4}[.\/](?:[1][0-2]|[0]?[0-9])[.\/]([0-2]?[0-9]|[3][01])\s*$/
if (!r.test(element.value)){
alert("Date format is YYYY.MM.DD")
element.value=element.defaultValue;
element.focus();
cancelBubble=true;
return false;
}
return true;
}
</SCRIPT>

2) Try to use onkeydown event (see http://msdn.microsoft.com/workshop/author/dhtml/reference/events/onkeydown.asp )
3) Yes
<div style="position:absolute;left:20;right:20:width:3;height:100;border-left:solid 2 black;"></div>
4) Yes
<table style="border:solid 2 black;">
<tr><td>Cell 1</td><td>Cell 2</td></tr>
</table>