Ah ok! Point taken. I'm not saying it's the best strategy out there, I just replied to the poster saying that 1 base can only supply 3 rax for a continuous flow of units, that's it. I also added that it works for me in combat, I might not have played it against enough human players, that's true, but it did work whenever I applied it.
You might be a diamond or platinum player, I wouldn't know, and you can tell if it's wrong or right, but the speed is subjective and there's a long ladder before you even reach platinum, let alone diamond, so many of the players in-between might not think as well as you do.
The last quote has an obvious answer I think, I only put it because I might have already played against/with some of the posters here and if so, it should be easy enough for them to watch the replays.
70% marauders is way too many marauders. Marauders are there to soak up damage and die. Marines have much higher DPS & should be your primary damage dealer in an infantry army. (I mean, unless your opponent is like "HURRRR ONLY ROACHEZ GOGOGOG.") But having a ton of marauders means like... zerglings, mutas, chargelots, immortals will annihilate you. You'll be able to charge into tanks & colossi more easily, and you'll crush roaches and (to a lesser extent) stalkers. But you leave a lot of gaps there.
I stand behind my claim of 3rax per base. If you have 4 tech lab rax & only some of them are making marauders, you don't really need 4 tech lab rax. At 2 tech lab + 1 reactor raxes, you really are spending most of your income. You could probably afford to have a 4th rax (no addons) making marines, but you'd be broke--forget about upgrades.
Being in battle constantly and thus not having to build depots changes this story a bit. But those situations shouldn't last too long. I mean I think they happen 1) when you're under heavy attack & are barely scratching by or 2) you cut economy, upgrades, and/or expansions to build a relatively large army quickly & push (still need depots here but you get to cut scvs instead, say).
Also, every game is different, but unless you or your opponent are in the fight of your lives, expanding by the 7-8 minute mark usually going to be pretty strong. Like if your opponent has a massive death army and you have to 1-base to not die, then fine don't expand (similarly if he's locking down your expansion some other way, like w/DTs). Or if he expands super-fast and you think you can break him, then delay yours and fight hard (this is pretty tough against good players). Otherwise, getting the second base as soon as its safe is quite important.
Basically, the more economy you can have (and still stay alive), the better. Experiment. You'll probably lose some games at the start if your sense of timing is off for this. But in the long run it'd probably improve your play.
The 3rax build I use is pretty "normal" but I would suggest trying it out. I wouldn't be surprised if the resulting amry you have at various time points is actually bigger w/the 3rax + expand + more production structs. You can be building out of 3rax from the get-go & then adding more rax (due to the expansion) around the same time you'd be adding your 3rd & 4th rax anyway. Give it a try. Get 1 rax at 12ish and the other 2 around 18-19 (after orbital at 16). Get stim pretty early on & add the others as you see fit.
And get medivacs. You will literally be amazed at how much stronger your MM ball is with the 3rd M. You can let the factory collect dust if you desire, but omfg get medivacs if you're using an infantry army. It doesn't have to be super early (I don't until after my first expansion), but they are SO useful.