Don't forget to live below your means, and buy an old clunker.
It is more cost effective to buy a reliable used car than a clunker. 2 or 3 years old, let someone else eat the depreciation.
Of course you want to buy your house, not rent, (you know, so you can generate revenue for yourself)
One's own home is an expense not an asset. In some cases, it is actually preferable to rent because your maintenance expenses are lower. Owning your own home is preferable solely because you can do with that home what you choose, rather than being limited in your ability to renovate, expand, etc.
Don't get sick or hurt or a disease.
Obviously this is impossible to predict. Which is why it is important for people to have secondary and tertiary sources of income that are not labor dependent.
Make sure the job you take will be the only job you have, so you can show the stability to get a loan to buy your house.
Stability is a good thing to show if one is applying for credit. However, one can have multiple jobs, but you do want the primary job to show stability. So you are correct here.
Don't buy with loaned money, as interest costs money, so buy everything with cash
Loans are fine provided that the money being borrowed results in the ability to purchase an asset that generates revenue. For example taking a mortgage on a rental property producing $1000 in rent, but the mortgage payment is $700 per month. While it is preferable to not have any debt, there are some instances where taking on debt is reasonable.
and don't let real life get in the way of your plans.
See my answer to getting sick or hurt, the same applies.
Don't let your old clunker break down.
Which is why you shouldn't buy an old clunker. Additionally, having secondary and tertiary sources of income allows one to have enough money coming in to deal with expenses as they arise. This along with proper budgeting should address any issues with unexpected expenses.
Don't let your roommates lose their jobs. (if you are living below your means, you will have roommates).
Roommates are not a necessity. In fact, I advise against it for the reason you stated. There are plenty of affordable apartments out there. If it turns out that one's income is not sufficient to afford one, then they have the choice to work additional hours, secure skills to earn more money and/or relocate.
It is all so simple, people are just too lazy and greedy!!
Granted you are being sarcastic, but this is the one thing you said that makes any sense. In large part, people want possessions but are unwilling to work to obtain these possessions. Or, as soon as they earn enough money, they spend it. One can have more possessions than they could ever dream of, but they need to deny themselves in the short term, so they can enjoy life in the long term.