1) Within the onSelect function, 'this' refers to the input field. So you can find the field's position using standard jQuery: $(this).offset (). Then place your popup of events accordingly.
2) You can use the beforeShowDay setting to highlight dates. This is a function that takes a date and returns an array with the first entry being true if selectable, false if not, and the second entry being a CSS class to apply. For example: $(selector).datpicker({beforeShowDay: function(date) { return [true, hasEvents(date) ? 'starred' : '']; });