Help please: ram memory low, kernel task high, macbook overheating

It's not the drive. Yours has already been upgraded to an SSD:

Drives:

disk0 - KINGSTON SV300S37A240G 240.06 GB (Solid State - TRIM: No)

Internal SATA 3 Gigabit Serial ATA

and that is about the only way to get speed from that computer. Your SSD speeds, at about 250MB/sec are at nominal for that model and drive interface. That is max speed for a 2010 model.

Frankly Chrome concerns me as well. Look at Memory usage:

Top Processes Snapshot by Memory:

Process (count) RAM usage (Source - Location)

Google Chrome Helper (Renderer) (11) 1.55 GB (Google, Inc.)

kernel_task 866 MB (Apple)

EtreCheckPro 601 MB (Etresoft, Inc.)

Google Chrome 449 MB (Google, Inc.)

mdworker (9) 389 MB (Apple)

It and its minion "helper" are using 25 percent of your memory.

Chrome has a reputation for gobbling resources like a hungry hippo and draining notebook batteries fast. As your RAM is at Max and you have the fastest hard drive possible, I do not think you have the resource to run Chrome. If you must run it, quit it when you are through using it. Safari and FireFox are much easier on your resources.

You have some apps running that look like system hacks or mods with which I am not familiar. I would download MalwareBytes for Mac for the developers' web page (https://www.malwarebytes.com/mac/ ) and see if it identifies MagaUpdate as adware or a "PUP" (potentially unwanted program).

Well, may not be conclusive, but this is what I saw:

1. You have a snail speed 5400 rpm hard drive - does everything (read/write) molasses like slow.
2. You are running resource hogging Chrome
3. You only have 8 GB RAM - unfortunately, that is how high your very old Mac can go. Fortunately, the memory pressure is showing green which means it is ok. But, with the processor intensive stuff you are running, you should have at least 16 GB and a newer more powerful processor.
4. Even if you could install 16 GB RAM and get rid of the 5400 rpm spinning drive, you still have completely outdated 10 year old computer hardware and you are asking it to do more than what it can.

So, I'd suggest you start saving for a newer model. In the meantime, do not run processor intensive apps at the same time (includes Garage Band as well) and make sure you quit one before starting another. Do not have too many tabs open in Chrome.

Which reminds me: your battery status is "replace soon" with more cycles than the average expectancy. I'd replace it now before it starts swelling and causing damage to other parts (that is if you are going to keep it for a while).

And, what are you using the 5400 rpm drive for? Running Garageband or whatever? or simply storage?

I see. Must have done the dual drive thing.

Still, the SSD was the boot partition at the time of the test, and the read/write speedsspeeds recorded confirm that:

Performance:

System Load: 1.53 (1 min ago) 1.56 (5 min ago) 1.84 (15 min ago)

Nominal I/O speed: 0.40 MB/s

File system: 23.52 seconds

Write speed: 228 MB/s

Read speed: 266 MB/s

Were it booting from the Hitachi, the read/writes would be in the 50-70MB/sec range common to 5400 rpm drives on a slow 3GB/sec SATA drive bus.

I believe the OP has two drives (possibly swapped the DVD for the SSD):

I read at another forum that any antivirus/malware software is not recommended in macs as they have their own system which does a good job and that the two would clash.

Most troublesome anti-virus stuff was ported from Windows versions and are not recommended. Yes they clash with built-in protection in macOS MacWareBytes is the product of a respected contributor and Mac expert here and does not cause conflicts in my experience. You can use the free version in stand-alone mode to scan for adware and then close it. That way it is not running all the time.

Kernel_task and WindowServer are responsible for lots of important Mac things so they will be near the top of the the AM list regardless of what you do or don't do.

I would review some of those third-party installs like DNSCrypt, gfxCard status, and MegaUpdater. Try disabling them one as a time as see if things speed up. I've not heard of the first two but they make my "MackySense" tingle, and I have seen several recommendations here to remove MegaUpdater.

Does anyone happen to know or could recommend any MBP models that don't have issues with external monitors - or are there are any MBPs that have the integrated graphic card only and if so, is it possible for those to be connected to the external monitor? That would help me a lot when choosing a newer model.

I think it would be easier to get the MacTracker database, free in the Mac App Store, to help with that. It shows full details on internal hardware that often is not in Apple's published specs. I am hoping that my Mid 2012 MBP with upgraded RAM and an SSD lasts a long time because I am not impressed with MBPs made since!