Well, your points are not actually bad but the most important knowledge that a new Bitcoin investor needs before applying security to his holdings is how to buy. If an investor knows how to buy he can also know how to secure his Bitcoin, at that moment he believes that it is his asset because he exchanged his fiat for Bitcoin through p2p, at this first point when he has purchased Bitcoin he doesn't care if he has make profits or not, the next step is for him to send the Bitcoin to the wallet he will use for holding. Which means after buying, the other important step is sending.
As a newbie to Bitcoin investment, you also need to calculate the figures of Bitcoin you have, so that while sending from the exchange you bought Bitcoin from to the wallet that you will use for holding you can be able to figure out the fees for your transactions so that you will know the figures of Bitcoin that you will receive.
Personally I feel a newbie should learn about a secure wallet and method to implement
the important thing is buy the Bitcoin first before any other thing, while waiting to know a good and reputable wallet to hold your Bitcoin you might have missed some good opportunities that won't come back again. Now let's say you wanted to buy $200 worth of Bitcoin, and you are still waiting because you are contemplating about a more secured wallet, you might miss the dip (if you are also the type that want to buy during dip period) and you might still end up not buying at all because you haven't seen any wallet that's suitable for you. Am only saying that you should buy first before making any other move that's why buying is the most important knowledge a new Bitcoin investor needs to know.
Before learning how to * or sell.
You are still getting it wrong, as a new Bitcoin investor you don't need to sell yet because you haven't achieved anything (unless you are not investing for long term).
Long term investment is the goal and a new Bitcoin investor who has applied DCA method should not think of selling his/her Bitcoin anytime soon because holding BTC for long term is not about sell and buying again (only traders does that), you only need to buy, buy and buy until 5 or 10 years of investment. Dipping your hands into your investment won't profit you anything rather it will make you not achieve a good portfolio.
I kind of not agree with your perspective on newbies not learning about a secured wallet first before starting their investment, in fact, this should even be the very first thing to do because we are talking about where you are going to store your funds here and should be taking with priority, So to me, I believe it quite a very good move and even a wise thing to do for every beginner out there as this is one of the basic stuff we need know before kick-starting of any investment in the digital/crypto world.
Well, the truth is that if it's about Bitcoin investment the person need to start as soon as possible because every time waisted Bitcoin will either go down or goes up and if Bitcoin dips during the time the person haven't buy Bitcoin it will take a long time for Bitcoin to dip again. IMO if one has bought Bitcoin already, how to secure it will not be a problem, that's why I said earlier that the first knowledge a new Bitcoin investor needs is to know how to buy Bitcoin before learning how to secure it.
If you haven't own an asset and you are learning how to secure an asset what will you secure after learning it?
Learning how to secure your bitcoin before learning how to buy bitcoin makes no sense. If you already bought Bitcoin from an exchange, while learning how to secure it you might learn more things (is like using one stone to kill two birds), while learning how to secure your Bitcoin after buying Bitcoin you will also notice the price fluctuations, so it's not bad to learn how to buy Bitcoin before learning how to secure what you have bought.
Buying and HODLing bitcoin is very stressless,
I understand the peace when we just buy and hold bitcoin for long term. But at the same time, we have seen what happen when there is a bear market and price dips. People begin to panic a start selling off, and also don't forget how life even can occur,
Using DCA method to invest on Bitcoin is the best option because it gives us the peace of investing at our own comfort, and it doesn't put us in to the pressure of investing.
However, the truth is that only people who are not disciplined to invest on Bitcoin for long terms only panics when Bitcoin is dipping because their don't see the dip as an opportunity to invest more. They only want Bitcoin to skyrocket within a specific time of there's so that they could sell off and make profits on their own. But they should try and understand that Bitcoin is not a get rich quick scheme and they should also understand that for them to profit well on Bitcoin, they have to invest for long term.