What would be the top things you would advise on or suggest to someone whos thinking of buying BTC?
Mine would probably be;
1 Before investing, spend time learning about cryptocurrencies and blockchain in general
2 Dont look at it as get rich quick scheme, but as a long investment
3 Learn ways to keep your bitcoin safe and secure.
All your points are correct but some more points to be added like,
4) If you know trading then buy in dips and sell in high, this way trading your buying price will get low and you will be in profit if you entered in high price.
5) Trading is good and try to invest by dividing your budget so that you should be able to invest if the market dips .