Thurso
Hi Grenlyn, if you are camping at Thurso I assume that you intend sailing from Scrabster! The ferry which sails to Stromness is a modern ship, with excellent facilitys. Thurso is abusy little town, no major traffic probs tho". If entering town on A9, as you cross estuary bridge, immediately turn right down by the Ford garage, you will be on the original dock side.
Continue straight along, you will pass a cafe on the left,(brilliant fry-up) then ahead of you the new esplanade opens up. You can park free on thier, while you get to know the town. As for wilding o/night thier, Iam not sure.
On the outskirt of town, towards Scrabster, there is a campsite overlooking the sea. This is all within strolling distance of the esplanade, take a stroll, and sound the place out.
As for midge repellant! I have not needed it on the Orkneys, the breeze blows them back to Mainland.
Happy travels Nig.