As replied before,
1) It is possible, but you may have to carry out some manipulation of the output in excel, and also intelligently use the selection screen.
2) An Adhoc query is just a selection of data from the database and output, it does not carry out any intelligent filtering based on the combination of fields.
3) There is a way of inputting some snippets of code for specific custom fields in an adhoc query, you could get the help of an ABAPper and explore this option.
4) There are standard reports for Absence and Attendance, do they not suffice to get an absence list?