In one week you need to decide between nortbound and southbound itinerary. Not enough time for both.
I will not build itineraries, but list places worth a visit.
North: Preveza town (either on town quay, or on anchor in front of the quay. In bad weather
, in the anchorage to the north of/behind the new marina.
Parga bay (on the mainland)
Mongonisi bay in the south of Paxi. Anchor.
Gaios in central Paxi - town quay.
Lakka - north Paxi. Also town quay.
Corfu town - Mandraki sailing club under the Venetian fortress
Tranquil bay east of Nydri.
Spartochori in Meganisi - deep anchorage, or buoy of Spilia restaurant or Spilia restaurant pontoon.
Sivota on the south tip of Lefkada - anchor or restaurant pontoon (there are several).
Asos anchorage - west Kefalonia (day anchorage or night in good forecast).
Aya Eufimia - east Kefalonia
Vathy on Ithaca.
There numerous beautiful bays and coves to in the islands south of Lefkada marina that this place would not suffice to describe that may be excellent lunch stops. You will see them on your way to any designated night stop.