pioneerfix

The 100% CPU usage really shouldn't matter.

You can try opening Ryzen Master and overclocking it a bit to like 3800mhz at around 1.3V

I see no mention of gaming here so, a video card upgrade might not be the answer to your problems.
 
A RAM upgrade to 16GB and above is your best bet.  Maybe an SSD upgrade down the road could somewhat help with your use case as well.

No it is not because the voltage will be different. Don't quote me if I'm wrong, I am almost positive though.

memory sticks, not cards.
 
the faster stick will slow down to match that of the slower stick. Should still work.
 
the voltages are the same. All DDR4 run at 1.2V, excluding overclocked sticks.

Both memory sticks will run at same frequency, supported by both memory sticks... 2133 Mhz.
 
Each memory stick has a tiny memory chip  that stores several presets including some "default", "fall back to safety" standard ones. Pretty much all memory sticks MUST include those safe presets, and as far as I remember, the standardized safe presets are for 2133 Mhz and 2400 Mhz maximum.
 
So the 2133 Mhz stick may have Profile 1: 1866 Mhz at CL 12 and voltage 1.2v  , and Profile 2 : 2133 Mhz at CL 14 and voltage 1.2v
The 2400 Mhz may have Profile 1 : 2133 Mhz at CL 11 and voltage 1.2v and Profile 2: 2400 Mhz at CL 14 and voltage 1.2v
 
The bios looks at both and sees that both memory sticks have a 2133 Mhz preset, both run at 1.2v on that frequency, and then it picks the most compatible CL between CL 14 and CL 11, which would be CL 14  (with CL, or latency, lower CL is better, but if the stick doesn't support a low value, there would be errors, so the bios would default to use the higher latency that would be supported by both sticks but may make one of the sticks ever so slightly slower)
 
Some sticks made to run at higher frequencies will need 1.35v to run, like let's say a 2933 Mhz stick... such sticks will run at lower frequencies like 2133 Mhz or 2400 Mhz with lower voltages like 1.2v
 
In theory you can risk running the 2133 Mhz stick at 2400 Mhz and run both stick at 2400 Mhz, but you'll have to be careful enough to use higher values (more relaxed) for some timings to reduce the risk of errors. If the memory stick is made of really bad (or better put ordinary, value, cheap) memory chips, those chips may need slightly higher voltage to be stable and cause no errors at 2400 Mhz... so you may have to raise the voltage to 1.25v for example, from the default of 1.2v
 

I would say that your current config is pretty good. I think you can also overclock your CPU and IGPU. Overclocking IGPU will give you very good performance increase. I think stock ryzen cooler is capable of handling decent Overclocking.
In future if you want to change to 2400G together with the fans.. you can go with 2 x 120mm Noctua Static pressure fans. They will be more than enough.
 
Temperatures upto 70 are pretty ok while gaming I would say because Tjmax is 105 degrees C... so it wil still be pretty far away.
 
I personally think that trying to keep temps down to 30-35 is madness that extreme enthusiasts would want. I personally have 2400g and I used it at stock clocks at 45-50 degrees with just one exhaust fan at back and with stock ryzen cooler. Without any intake fan. And this was while playing GTA-V...
 
so you are good to go man..

Build something like this....
 
PCPartPicker part list / Price breakdown by merchant
CPU: AMD - Ryzen 3 2200G 3.5GHz Quad-Core Processor  ($94.59 @ SuperBiiz) 
Motherboard: ASRock - AB350M Pro4 Micro ATX AM4 Motherboard  ($74.39 @ OutletPC) 
Memory: Patriot - Viper 4 8GB (2 x 4GB) DDR4-3000 Memory  ($86.98 @ Newegg) 
Storage: Crucial - MX500 250GB 2.5" Solid State Drive  ($69.99 @ Adorama) 
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive  ($59.79 @ OutletPC) 
Case: Cooler Master - MasterBox Q300L MicroATX Mini Tower Case  ($38.99 @ SuperBiiz) 
Power Supply: Cooler Master - MasterWatt 550W 80+ Bronze Certified Semi-Modular ATX Power Supply  ($45.98 @ Newegg) 
Total: $470.71
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-11 10:02 EDT-0400
 
U can even opt fr RYZEN 5 2400g fr slightly better performance

go with the 2200g, and any LGA 1151 v2 will do for the 8100

If you are going to relay on integrated graphics for a while, lets say a year maybe, then get the ryzen 3 2200g or the ryzen 5 2400g for the extra 4 threads. But that is only of you are desperate for a pc right now tho. My best recommendation is to wait until the summer or maybe even next year to see what will happen with gwu and memory prices. We are already seeing a drop in GPU prices because krypton currency is harder to mine now, and memory manufactures have a law suite against them now. So we should see a price drop soon.
 
I think you should wait and save up more money and wait for prices to drop so that you can get a good graphics card and the i3 or maybe even a i5. I would definitely NOT recommend waiting and saving a little more money as for right now.