Just a quick observation ... as has been pointed out, Plymouth isn't especially local to Dorset and wouldn't be on my list of places to visit when in Dorset. Much the same re. Torquay ... I only live 15 minutes from Torquay (and half an hour from Plymouth on a good day) and wouldn't rush to either if I was trying to see as much of Dorset as possible. You could say visit Dartmoor but it's not particularly local to Dorset. If you DID happen to want to explore South Devon then say so and I, among other, will offer suggestions ... but from what you say you want to explore Dorset, not Devon and there aere some goos ideas listed above. Don't forget that iconic (if that's the word) advert for Hovis breaad - that was filmed at Gold Hill in Shaftesbury - and Cranbourne Chase is nearby

If you were to fancy venturing just over the border from Dorset towards Yeovil then I would say the Yeovilton Fleet Air Arm Museum was a really good day out - but really warrants at least half a day as there's a lot to see.

Don't feel too tempted to actually visit Yeovil though , it's probably not worth a detour.

If you went to Lyme Regis then maybe stop off at Bridport for a bite to eat and wonder why the pavements are so wide (the answer lies in the making of rope) and if you're going to Bridport you ought to stop off at Burton Bradstock to see the quaint cottages etc. I suppose Lyme regis is worth going to - if only to say you saw the Cobb (where they did the filming) but don't hold your breath - it's a fairly standard, busy, seaside town with all that you might ordinarily expect. Ditto Weymouth is OK but busy but not what you'd call cosy and pretty. If you're in Bridport then there are worse places to stop off for another bite to eat than Beaminster (pronounced Bemster)

As was said, the steam railway adds a little extra something at Swanage and Corfe Castle is OK (who remembers the fabulous little film 'Nuts in May' with Alison Steadman? ... that was filmed thererabouts).

Get your kit off at Studland naturist beach and wonder at the prices of houses at Sandbanks (near the red squirrels on Brownsea). Poole, Bournemouth and Christchurch are popular but, again, gonna be busy (ish) ... if you go much further east you're in New Forest territory.

There aren't any motorways in Dorset and some regard it as a bit sleepy in parts. To be honest if I had to move anywhere I'd look closely at Dorset. But it's not cheap, especially toward the coast. In fact if you ask Avant he'll add some more coz he lives there.

Have a good trip.