We really like it. It's very safe and not rough in terms of people. The town does have some less attractive buildings shall we say but most of them are slowly being redeveloped now. See the new Nici Hotels development of the Hotel Victoria, it's going to be very swish. I think some people at least must think we're up and coming! The stag dos we're perhaps known for have all but gone now, I hardly see any in town any more, I think they must go abroad now.
It is certainly busy in the summer but that mostly affects the roads and carparks as long as you live actually in Newquay then you can walk to everything. You just need to a allow a bit more time for commuting or travelling to anything further afield in Cornwall. In practice though i find thta often the holiday makers are coming in on the roads when I am going out and vice versa when I am coming back so it's not so bad and you get used to it.
As there are so many beaches there is quite a lot of room for everyone so it's easier to get a spot without being on top of the next lot. Perranporth beach really does get absolutely packed in the main part, but even there if you walk to the East side (check the tide) then it's practically deserted. Plus if you live down here you will eventually get to know the lesser known spots in Cornwall where you can get away from everyone. What I like about Newquay too is that it is large enough that there is still a community and events and things going on all year which is nice.
It is 100% better to buy. Renting is near impossible regardless of how much money you have, the demand ids just too great. I hear of people with 6 months or more rent upfront to offer who can't find anything because it's just not there. Buy if you can. You can see I linked above there are some cheap houses available here, of course if you have money then there are dear ones too!
We bought our house 15 years ago when they were half the price they are now and have paid it off (we're in our late thirties/early forties) so we are much luckier than most but our friends have just bought on our street and they make it work on two average incomes. I'm self employed (lots of people down here are) and my OH does delivery driving so we're not minted or anything but we're frugal and we find the lifestyle and leisure type stuff in Cornwall very affordable because it's mainly based on the natural beauty and enjoying that. It must be all the shops I can't go in that's saving me money I suppose.
I don't have children (I know, why am I here, blah, blah, blah? The answer is penis beaker) but I have nieces and nephews. I think it's better to be in a larger town like Newquay if you're going to move down here with kids as then when they're a bit older they can easily walk out to see their friends or take the bus/train and there is a bit more going on for them.