Use Avast Free. Norton is a huge resource hog and, of course, it isn't free.
Lenovo make excellent laptops and have done for a long time. Not always the prettiest but some of their new models are actually stunning.
The HP Envy 15 is fairly well thought of. Again, pretty standard specs. Has a good AMD CPU. Ignore people telling you to go for Intel. Makes no difference here.
www.pcworld.co.uk/gbuk/computing/laptops/laptops/hp-envy-15-ah150sa-15-6-laptop-silver-10139156-pdt.html
HP's Pavilion x360 is a great example of how the specs drop because it's a 2-in-1.
You main consideration is a large HDD.
As for the extended warranty; they're significantly more expensive than if you insure it separately eg. through home insurance. I bet you'll have a pleasant surprise if you called them and added it as a named item. There is a massive spike in failures during the first 90 days when, of course, you're covered by statutory rights (SOAG) and regular guarantees and warranties. After that, the chance of a failure is significantly lower. Besides that, 3rd party repairs aren't undertaken enough as they're cheaper and easier than people think.
People will give up on a laptop instead of basic and cheap repairs (and then make comments like they need to replace their Windows machine every year
).
Even a new screen for many (non-touch) computers will cost about the same as 1 year's extended warranty. Are you planning on (or expecting to) breaking a screen a year? Of course it's a gamble but not one most people should take.
Surface Pros are stunning both in terms of what they can do and their versatility; I'd love to be able to justify one and I'm excellent at justifying computer purchases. I'd suggest though, it overlaps too much with an iPad for you to splash the cash on one. I don't think it can do things like update your satnav. Also, the largest model is 128Gb (I think) and that's quickly eaten up if it's your only 'computer' used for storing photos etc.