Much as I love Keswick, I wouldn't say it's a hotbed of "community, cultural things to do, good places to eat and a bit arty".
The 'Theatre by the Lake' is good, hosting far more than you'd expect for the size of town. There's also a small cinema.
Places to eat - a great deal of choice (sheer number of tourists), some good but it depends where you're coming from - it's not going to appear in a list of 'best places to eat in the UK'.
Community - poss not it's strong point. Obviously a lot of people are tourists/short-term lets. It's gets its fair share of crime (small town, limited things for people to do who aren't into walking/running/climbing), but probably not worse than most towns that size.
I realise my comments sound negative, so I'll go back to saying I love Keswick, but that's because I love the surrounding areas and fells. The town for me is mre of a base than a destination in itself, altho' for many others it is just that.
Maybe a trip up there would be worthwhile?