Yup, it's less than you think and makes the biggest difference. Anything like stairs / hallway I'd normally assume 2 days as the size will be bigger than you expect and more 'cutting in' and labour. Our living room was also 2 days but that's 7m*4m. Every other room has been a single day (£200 labour) + materials, based in Surrey as well.
I'd guess £5000 for your kitchen is way under unless it's very small, we spent about £7k on our last kitchen and that was 3m*3m and I got all the trades in myself and ordered everything online. Equally £5000 for carpets seems way over but you may want really expensive stuff.
Underlay is super cheap,
THIS is the best stuff and is £600 for 100sqm so you probably won't need much more than that (again, depending on the size of the house). Fitting we've been paying £50 for a standard square room (4m*3m). Stairs, hallways etc... will be much more. Then carpet cost is whatever you decide, starting at £10 per sqm up to about £50 per sqm. Work out your sqm that needs carpetting and then estimate based on say £30 sqm for carpet, £600 for the whole house for underlay, £75 a room fitting and misc bits (door bars) and say a few hundred for stairs and hallways.
Oh, we moved in when my son was 9 months old and since then we've had another. I'd say we managed to get rid of about 50% of the smell in the first month with lots of airing of the house, candles everywhere and stripping the worst wallpaper off ASAP (this makes the biggest difference).
