If an alternate location is not practical, consider storing items at various locations around your home.  Not everything needs to be on shelves in the basement.  Spread things out so that if the basement gets flooded, you still have dry items in the upstairs bedroom.  Use your imagination and don’t forget to do the very best you can to package everything so it is resistant to moisture and pests.
Not so sure I agree with some of this list. Sure, you need to clean water, shelf-stable foods and alternative ways to cook it, but not so sure I would recommend beginning preppers bother with a rifle or seeds quite yet. I would suggest they worry about items like a comprehensive first aid and hygiene/sanitation concerns first. You need to be able to get through a disaster before you should worry about a long term survival scenario.

Emergency Radio- Even a very severe disaster is unlikely to obliterate communications grids entirely. Pickup one of the hand-cranked or battery-powered emergency radios so you will always be able to passively receive information so long as authorities are transmitting. Some nicer models include a flashlight or even USB charging ports. So long as you have the muscle, it will have power.
One can infer from commentary in newspapers and writings of folks commenting on the current scene that weather was bad. I can remember folks still talking about the winter of ’88 when I was a kid. I do believe as a personal belief that war creates world wide different weather patterns. I believe it is due to the smoke and dust thrown into the air by shelling, now also bombing, and fires that create some temporary misalignment in world weather patterns. I know from personal observation in the desert that contrails can affect the temperature on the ground locally.
Regarding the general category of water purification, you have essentially combined reverse osmosis with UV disinfection PLUS the necessity for solar and/or gas generated power. Take away the essential electrical power and you still have to boil your water. If you do the math, you could invest up to $2500 for your version of water purification. That’s a “big ticket” indeed. Once again, there are abundant information sources that provide instruction for long term water purification that cost far less.
The funny thing about freeze-drying is it’s kind of an exception to the rule. Removing all the water from a floret of broccoli, for example, doesn’t turn it into something new; it simply transforms it into a slightly lesser version of itself. “Once you change the physical structure of something by drying it out all the way,” Allen said, “the texture is never really the same.”
And not everyone is rational. The prepping movement contains overzealous elements, particularly in the US, where natural disasters are bigger and badder and, well, the guns. But those signed up to the movement in the UK are like you and me: relatively normal, with the odd quirk. They just keep a half-tank of petrol in the car at all times, and at least a month’s worth of food, and an alternative way to heat their homes in winter if the gas goes down.
As someone who reads a lot on the internet, you have likely come across many authorities with “expert” advice on one topic or another.  This is where the gray matter between your ears becomes the most important tool in your box of prepper skills.  Think it through before you unilaterally apply someone’s expertise to your own situation.  Let me repeat: this includes advice and suggestions from this website!
Common preparations include the creation of a clandestine or defensible retreat, haven, or bug out location (BOL) in addition to the stockpiling of non-perishable food, water, water-purification equipment, clothing, seed, firewood, defensive or hunting weapons, ammunition, agricultural equipment, and medical supplies. Some survivalists do not make such extensive preparations, and simply incorporate a "Be Prepared" outlook into their everyday life.
Luther understands the need for such a policy. A month after she gave birth to her first daughter, her husband lost his job. “We had absolutely no money coming in for three months,” she recalls. “We had a whole bunch of bagels that I had gotten on sale in our freezer, and we had some peanut butter, and we had some vegetables in our garden in the backyard. And that was absolutely all we had to eat. It’s terrifying when you’ve got a new little one and no money to take care of her.”

EMP attacks, both natural and otherwise, are genuine threats. Once considered “conspiracy theory,” EMP attack threats have been featured in mainstream media publications such as Business Insider and Bloomberg. Natural EMP threats are proven as well. The sun’s solar flares have (and will again) wreaked havoc on our planet during non-technology eras. In 2012, it almost happened again.
MREs are a very convenient prepping food because aside from the pudding they do not require the addition of water. These meals also include a built-in heater so that you can warm up your meal no matter where you are and eat right out of the bag. They are easy to carry with you, making them a good addition to your bugout bag, and they come as a complete meal, even down to the salt and pepper.

A lot of us don’t truly appreciate how much spices can add to our dining experience until we don’t have them. While they don’t have a lot of calories, I think they are important for preppers to put back. A lot of spices can be bought by the pound for a low cost. I cook every day and sometimes it takes a few years to go through a 1 lb of some spices! 

“The answer is you probably could,” she said. Though research suggests it might cause a mild depletion of vitamin C and other antioxidant chemicals, she explained, freeze-drying fruits and vegetables doesn’t have any significant impact on their nutritional value; packaged as stand-alone ingredients, they can even make for a healthy alternative to more caloric snack foods.