Falmouth is lovely, I know it very very well as I grew up nearby and family live there. However, the character of the town has changed a lot since the college (now a uni) began expanding at a rate of knots. There are now big issues, pretty serious in some areas with parking due to so much of the older housing now becoming multi-resident and every tenant has a car. It's not uncommon to park nearly quarter of a mile from home sometimes. And the students don't always make for the best neighbours - obviously it depends on the students as some are lovely, but anecdotally I know of far too many negative stories. And they are not always peaceful on their return from the pub (personal experience!) - yes, you can get that anywhere but it never used to be that bad in Falmouth, and the number of pubs has decreased, not increased.
It's a bit isolated geographically as to get most places you have to drive several miles along the A39. If there are accidents, or trees come down or flooding happens at the Norway Inn near Devoran, you've had it as the side roads can't take the diverted traffic!
It's true about it being permanently damp in the off season though! Never bothered me, mind.
That said besides those issues it is a delightful place or my family wouldn't still be living there. The local residents are very friendly so long as you're not annoying, and there's a strong sense of community with people accepted for who they are.
There are things to do and the walks over the cliffs to Swanpool and even further to Maenporth are truly stunning, as is Pendennis Castle and the headland views up there. The shops are interesting, fewer chainstores than in many places, and there's lots of pasty shops. The various boat trips along the Fal or out to sea are fantastic. The views across the river are gorgeous. And the railway line into Truro is very fast, albeit infrequent.
Sadly I have only visited Edinburgh once twenty years ago so cannot comment!