This is why I love these strategy forums, you can get so much advice from different styles of playing. Where as dejai seems more of a methodical player with his limitless supply of build orders for every race where as I tend to be more mechanical and mental leaning who tends to focus on getting the basics crisp so that I can plug in virtually any strategy I want. Neither way is wrong, and neither is right they are different ways of learning and thinking. Where he gave you some great builds that work very well, I am going to give you some ideas to keep in mind to make his build order work very well. Any criticism is not a put down, it is constructive only so do not take anything that sounds mean personal at all just take it at face value.
First I want to point out a few things I thought you did well in all five matches. You had really good creep spread, it was not the greatest ever in all the land, but you actively spread it throughout all the matches that lasted over a certain amount of time. Spreading creep is always a good thing to do as zerg since all ground units benefit from it. Secondly, you always seemed to try to expand which alot of players simply do not do, zerg or otherwise. They try to one base and power rush and that usually will not work against someone who has a good defense off of two bases since the two base person can produce more units faster after the battle compared to the one basing person. Also, alot of the times you had the bigger economy compared to your opponent which is great and always a good thing to have.
Sadly there are more things that you did wrong than you did right, and there is absolutely nothing wrong with that if you understand what you did wrong and wish to fix it. Mistakes are not bad, it is doing nothing about them that is bad. I am just going to quickly go through the list of things I noticed that were not ideal. Again do not take this personally, I do not mean to be mean just factual. Very high money count, not enough workers after expanding, not enough fighting units when going into fights, getting supply capped, high queen energy, lack of scouting, bad mouse control (on the last match in metalopolis there were times when alot of zerglings were trying to attack just one of the stalkers instead of surrounding all of them), the hatcheries were not rallied (the drones were rallied to the minerals, but the units spawned wherever because you did not always give them a rally point), you clustered your overlords directly over your base instead of spreading them around the map and gaining vision, you did not use many control groups. Do not think that this stuff is something you can not overcome because it is, it just takes time to do so. So do not get sad and think "I suck and can not play" when all you really need is a practice of the fundamentals which can let you spread out from there.
It is great that you have seen the day9 episode of "the mental checklist" because that is something that will easily help anybody get a solid grasp of how to play starcraft 2. It will not make you a diamond player in one day, but it will make you better. This is what I want you to do the next time you start playing. I want you take a build order, use the one dejai suggested because it does work very well. And with that build order I want you to always do the next four things:constantly build drones, do not get supply locked, keep your money low, and watch your queen energy and try to spit as often as you can. If you keep practicing those things you will very easily lose less and less to whatever strategy the opponent is using. Your current problem is not the strategy you are using or the strategy that the opponent is using, it is just your execution.
There are numerous ways for you to keep money low if you think about it. Just keep building stuff all the time. If you have larvae, build overlords and units. If you dont check to see if you have upgrades you can research, or defenses you can make, or perhaps making additional expansions or just extra hatcheries in your base to make more units. Making overlords, units, expos, and checking upgrades is more of a proactive way to keep your money low which is what you want to evolve to, while making extra hatcheries in your base is more of a reactive thing that happens if your money is too high and you cant spend it. If you are constantly pumping drones, units, overlords, upgrades, and expoing you will not really need to build extra hatches in your main since you are already keeping your money low. And making additional unit structures is a great way as well to keep money low.
I am not going to lie, at first you will probably lose doing this. But winning/losing does not matter when you are trying to get better with your mechanics since getting used to your mental checklist is what you are really trying to do. Eventually you will get to a point where you always are making drones, always keep your money low, spend the queens energy, and are rarely supply capped. At that point you can then say "well making 200 zerglings is worthless if they get A voidray. I want to try using something else". When you switch you will already remember the basics of your mental checklist and just be able to substitute your 200 lings, for like 50 hydras or whatever you wish. At the stage you are right now even the one build order that never loses to anything at all might not help since you do not have the mechanics to currently do it. Again, there is nothing at all wrong with that, nearly everyone started where you are right now. There are but a rare few that were naturally gifted to instantly be the best ever in this game.
To answer some of your questions in the previous post: the best way to scout if they are bunkered in and have AA is to sacrifice overlords. They are a very relatively cheap way to scout, and since you are making them since you do not want to be supply blocked you will easily be able to recover from losing a single overlord. A tip you could do is to have a few overlords floating near their base, and then have an overlord near each expansion so you can see if they are trying to expand anywhere. You must also realize that the more defensive structures the opponent has, the less actual units they have. And a general rule to think about is, if the opponent is contained into their base you can probably safely expand. It does not always work but it a great general rule of thumb.
A great way to always remember your mental checklist is to get a post-it note, and stick it on your monitor or somewhere in your field of vision for you to always see and remember to do those four things that I suggested. (low money, drones, supply, queen spit) And constantly keep those things going through your head at all times. After awhile you will not need the post-it at all since it will become ingrained into your head for all time, you will be making drones and overlords in your sleep. In a battle it is a bit tougher to do since everyone has their own mental checklist in their head before they even play that says "always watch the fights". It takes awhile to break yourself of this habit but it is necessary to not forget to build probes, units, and make sure you are not supply locked even during battles.
The "saturation" of any mineral line is 3 per gas, and no more than 3 per mineral field but at least 2 per mineral field. So for the standard 8 mineral patch expansion or starting area you want between 24 and 30 drones for saturation. However as a zerg you will definitely want closer to the 30 drones per field since the drones themselves become the buildings. I would suggest that you lean toward over saturation so that you will already have extra drones ready for the time your next expansion is ready. I am sorry for this very long diatribe but sometimes i just get on a tangent and can not stop until it is done. If you have any more questions at all just ask, most of the community will be happy to help if they can.
HOLY MOLY THIS WAS A LONG POST!!!!!!!