I think people over there are over complicating things, i'll give you straight answers:
1- The best upgrade for your PC right now, Assuming you want to play games with higher FPS is a GPU. Graphics cards, yeah one of those.
2- Your PSU (power supply) is totally BONKERS. I'm not even talking about the wattage, is just that i dont recommend to anyone use UNBRANDED PSU'S.
What i mean is that you should get a trusted branded one like corsair, EVGA, Antec. Preferrably with 80+ Efficiency certficates. You cant go cheap on the PSU since a crappy one can blow your PC to the air.
3- If you had a "real" 400w PSU, i'd just recommend to you to get a Low profile card or even a midrange one.
But that chinese one you're using is pretty unstable, have that in mind beforing updating your pc further!
4- I dont think you need a CPU upgrade for now. your third gen 3200G has 4 cores 8 threads at 3.6 Ghz, thats enough to power a lot of decent graphics cards already!
The "People" you are referring to, have more experience in the last year working on and with computers, than what you have in your entire life. Period.
As to your "recommendations", let's take a look at those.
Yes, obviously a graphics card is a no brainer for a system that doesn't have one, so that's pretty much a foregone conclusion, but it requires that there is also a satisfactory power supply in use.
So your response is that you don't recommend an unbranded PSU, AFTER they already said they have a RAIDMAX power supply. If you're going to make recommendations on power supplies, at least have some kind of knowledge about them AND hopefully take the time to actually make recommendations based on what the OP has said they HAVE, which isn't an unbranded unit, but it might as well be because it's a pile of crap anyhow and if we're being honest and making legitimate recommendations, it probably shouldn't even be used with the system as is, with NO graphics card installed, much less WITH one. So, some kind of decent quality power supply in a capacity that is acceptable for whatever graphics card they decide to go with, is and should be the first thing on the menu.
I can agree about the CPU, it can work for now. It's no worse than a lot of systems really, running i7's from years past that are also 4/8 and still hanging in there so swapping that for something more capable can definitely wait until down the road if it needs to.
As far as having a "real 400w" PSU, and it being able to be used with a "low profile" or "midrange one", what is that even supposed to mean? There are low profile cards from many different performance levels and tiers, some of which will definitely not do well with only a 400w power supply, no matter how good it is. And as far as "midrange ones' are concerned, there are approximately ZERO midrange graphics cards from this, or any of the last four generations or so from either AMD or Nvidia, that I would feel at all comfortable with recommending that a 400w power supply is sufficient for. Practically all midrange cards from the last three or four generations have been in the 500-550w range, and could MAYBE get by with a really good 450w unit, but I would expressly not recommend doing so. You'd be pushing your luck, living at the edge of a noise level that is tolerable and almost certainly shortening the life of the power supply as well. Not to mention, putting the life of your card on the line since the PSU would likely be "living" in an output range that makes it very unlikely that it would keep within the ripple and voltage regulation ranges that it would have had it not been in use with such a taxing configuration.
So there are your straight answers, doesn't seem terribly complicated, and certainly not over complicated, to me. Furthermore, if you really don't know what you are talking about, it's probably a good idea to avoid making recommendations to real people who are likely to spend their REAL MONEY on the half baked suggestions that often get made here by people who don't really have any, or very little, business recommending anything to anybody, ever. We really take offense at leading people down the wrong path, especially when you take the opportunity to also make derogatory or inflammatory statements while doing it.
And by the way, as Dszymborski noted, there is only a single stick of RAM installed in your motherboard, so the memory kit listed in the OP is obviously NOT what is installed in this system. It would be a good idea to verify that you actually have the amount of RAM installed that you think you do, as well as the rest of it's specs.