I live about 6 miles from Meva and the following is my personal view which may well differ from everyone else but you did ask…..
Meva is lovely, very picturesque and has loads going on in the tourists season but although there is a small local population it’s almost dead in the winter. I wouldn’t want to live in any of the tourist hotspots because they are all pretty much the same in that they are heaving in the summer and dead in winter. Lots of second homes and seasonal businesses. The South coast, which is where Meva is is much milder than the North coast, and much better to live in all year round, rubbish for surfing though. The north coast is stunning and I regularly go for coastal walks there, when the tourists have gone home, but would only want to live on the South coast, where I am. Distance wise it’s only about 20 miles between the North and South coast although it takes a lot longer to cover a Cornish mile than in most of the country.
It does tend to be very wet but not cold. The mild climate is wonderful being neither too cold in the winter nor too hot in the summer.
I would look at a large village or small town rather than Meva itself so that there is something going on all year round and, contrary to the views of some, the Cornish people are friendly and welcoming but…
We moved down here when I retired and have had an absolutely brilliant time and it’s like being on holiday all the time. After 4 years though I am ready to go home so will be moving back to West Oxfordshire.
I will still come back to Cornwall every year as I love the place but it will be for a holiday not to live permanently.
I do feel sorry if your friend can’t settle but agree it would be better to rent for 12 months until they are sure about where or whether they want to live here permanently.