Levels of aggressiveness should not be measured in absolute terms, but instead within the amount of discretionary income that you have, and so yeah a person with higher income could buy more BTC but that does not necessarily make him more aggressive than someone with lower income and who might be using all of his discretionary income to buy BTC. Maybe we can take some extreme examples.
One guy has $100 per month of discretionary income and he uses all of it to buy BTC.. This guy is quite aggressive and maybe even bordering on over aggressiveness (especially if he miscalculates his expenses or if he does not have reserves in place).
Another guy has $2k per month of discretionary income and he invests around $100 per week into bitcoin, which might be considered moderate and maybe even whimpy.
Well i total agree with you and I love the example you gave below, aggressive Investment is not only putting all your funds in bitcoin without having reserved and emergency, sometimes investing %70 of your fund in bitcoin without considering the level of your discretionary and emergency fund can as well be seen as aggressive. if you received $1500 and you invest $300 each every week, making a total of $900 per month left with $600, that is a bad aggressive Investment and surely the person is over doing it. because your bitcoin Investment should be done in a manner that you will not over do it. It will definitely affect you or Put you in a tight corner. If you Invest $900 on bitcoin how much will you use for feeding and running family expenses? Or how much will you set aside for emergency and reserved? Surely if you over invest in Bitcoin, the $600 available amount you will not be enough for emergency and reserved. Definitely it will affect your bitcoin HODLing. Though it depends on you and how you can be able to manage your family. If its you alone you can cope but if it's a large family I doubt if you can manage. The point of the matter is that don't over invest what you can not afford to lose that will make you to sell you bitcoin HODLing down the road because of not having a discretionary fund to back you up.
You can invest aggressively when you have the funds to do that, the most important thing is that you don't over do it, if not it will affect you, and you will end up selling some part of your bitcoin to cover up some emergencies that will arise. Your emergency funds should be in a good condition because that is what will determine how aggressive you will be in buying either monthly or weekly.
You seem to have a lot of the ideas correct, but I am a bit confused by your example, and also a lot of the time, once the emergency fund is set, then it is largely never going to be touched, absent an actual emergency and if you have some reserves already in place, you may well not even need to dip into your emergency fund since your reserves and you float should be able to cover irregularities.
Your own example is confusing because when you give examples the starting points should describe the income as compared with the expenses in order that we are able to figure out how much discretionary income is available for investing.. so if we see that the discretionary income is not enough, then the person is over investing, or if he had not already established an emergency fund and reserves then he might be over investing, but from your example we do not know enough regarding what is the actual discretionary income in order to be able to determine if he is doing too much.
I am not even opposed to a guy investing 100% of his discretionary income into bitcoin as long as he has a sufficient emergency fund and float - but if he has made miscalculations and does not have those back ups then he might end up having to dip into his BTC at a time that is not completely of his own choosing.
The emergency fund should generally be a minimum of 3 months of cash or cash equivalents - something that is fairly easy to access and is denominated in your local currency, yet I know some folks would prefer to hold their emergency fund in dollars, even if they have a different local currency, and so that might not be a problem as long as there are ways to easily move into the local currency or that the dollars would be accepted for expenses if you were to have to use your emergency funds for your expenses or surprise expenses.
What I was trying to say is that, if you are working and you are been paid $1500 a month and you are investing $300 every week on Bitcoin you are investing aggressively because if you invest $300 every week that is $300*4=$1200 for four weeks and you will be lift with $300 how then can you save your emergency, reserves and float funds remember this emergency, reserves and float funds those not just appear you save for it and you keep saving for it.
So if you follow the example I gave when you are lift with $300 how much will you save for your emergency, reserves and float funds and how much we be lift for you to run your expenses for that month. The only way possible is when you have already saved your emergency, reserves and float funds for years and is enough before starting your investment.
From my first example the investor has not established his emergency, reserves and float funds so if his been paid $1500 and then his investing $300 every week for 4 weeks on Bitcoin his over investing.