A basic appreciation for the ideas of variables and memory layout is more than enough to make cheats, and probably even cheats like these that you describe. I would have to analyse the ones in question to see what goes (
http://gbatemp.net/threads/reverse-engineering-golden-sun-dark-dawn-exp-multiplyer-code.272880/ for an example of something fancy) as it could be something else, and in any case it might be easier if you did also understand some assembly coding and general ways code works (if I can disassemble something and see exactly how it works it is far nicer than having to watch something change 400 times and sort of guess and fiddle to learn the same thing). However if all you understand is what hex is, what memory is, what data encoding is and so forth then it is more than enough to make cheats beyond infinite health, ammo and money.
The other stuff was more that though I can set a 32 bit value and then have FFFF be the max and 0000 be the minimum and have 3 values in between there is no point if I can count up instead and not have to do some kind of almost analogue interpretation. Equally modern computers have lots of memory so unlike some older systems where
every sperm is sacred no bit is wasted the CPU time needed to unpack data is worth more than the memory it might save to put two different variables into one 32 bit value, to that end to assign a 32 bit value but only count to 6 using it is quite fine to do and commonly seen in modern computers.
The rubber band stuff was just me pondering things -- if you want the AI to catch you up in mario kart you could have them have some odd powerup that you can not see and functions to handle all that, or have them teleport or have something else odd happen. If however you can write a function like if distance behind is greater than ?? then set speed to ludicrous speed and you have the option to do that in basic "CC" value* then that is far easier than messing with teleports and whatnot. If that room is there to go way over the normal max CC value that menus allow you then a simple cheat would be able to do it. That might mean mario kart is a unique case and other games might not have it so easy.
*it is less obvious in newer ones but if you look at the racers in 8th place in the older ones as you lap them (baby park in GC mario kart is a good example) then you will also see them going really slow so it might also be a simple way to make AI, and a simple way to ensure that random AI do not win each race to give the player a bit of a challenge in grand prix mode rather than just getting an unbeatable points lead.
Oh yeah learning to code and make cheats and hack ROMs will lead to you noticing things like that in every game you play. I don't mind it but some people come to regret being able to see such things.
When you spoke of constants and such it usually comes from safe coding (it is to that what teaching people about factorial numbers is to recursion) so I assumed you went from there.