.Idle hunting ONLY when warm

Electrical load is present(Headlight/Power windows/Power steering). Oil Leak Bought as used car recently. No hunting when cold or when no electrical loads are present. As soon as light or some other load is present engine starts hunting(600-1200 rpm).(More the load, worse the hunting, can stall with multiple loads). Dont know how old the battery or the alternator is.

Car consuming a lot of oil(Losing 1 liter sometimes in 1 week, sometimes earlier/later). No leaks overnight though(Checked with paper beneath engine). No noticeable blue smoke either. Have not checked coolant color though.

Thanks a lot for your time,

Jacob.