Is it a laptop or a desktop?
Desktop self-built: suitable screws - often referred to as "SATA screws" - are often included with the enclosure.
Desktop ready-made: when replacing HDD/SSD you can often use the same screws.
Laptop: see "Desktop ready-made
If you need new screws, they are called "M3 screws" (regarding diameter) and the length should be as short as possible. The best way to look for the right screws is to 1) know that you actually need them and 2) know how long they should be.
And: you are not the first to wonder about SSD screws :) https://www.google.com/search?q=ssd+screws+site%3Adigitec.ch
Funny question. I'm not sure if this product was even part of the Black Friday selection. But it can happen that another supplier can offer a Black Friday offer (or other promotion) at a lower price. Another product is then cheaper somewhere else. It is usually always worth comparing.
Yes, that should fit. USB 3.1 and 6 or 10GB transfer rate is sufficient. I have an enclosure from UGreen with the same specifications as the ICY Box. I use the hard drive on all my Macs (MacMini and notebooks from 2014). Works flawlessly.
What is your measured throughput rate? USB 3.0 has real throughput rates of about 450 MB/s (and not the promised 625 Mbyte/s = 5 Gbit/s). The transfer rates of the Samsung 860 are also very volatile, depending on whether you are writing, reading or what data type. I would consider anything between 300 and 450/500 MByte/s as "good". All these tests were carried out under laboratory conditions. With the IcyBox, throughput rates of "only" 260 MByte/s are reported. Does the MacBook Pro have USB 3.0 on all USB plugs? Maybe that helps, otherwise get back to me with a few more details.
According to the specification, your computer (if it really is the tower version) should have three SATA ports. You can therefore connect SATA hard drives (such as the 860 EVO Basic).
However, I cannot guarantee this, as Acer has not provided a diagram of the motherboard in the manual (and the pictures/videos available on the Internet are not certain).
If you really want to be sure, you would have to look on your motherboard (should be to the right of the CPU, 3 pieces, black or red connectors). Also check whether you have the power cable for SATA to hand (was included with the PC). Also check whether the 3.5" bay (bottom side near the front) has mounts for 2.5" hard drives (i.e. screw holes on the underside of the drawers)... in the worst case, you will have to buy a 2.5 to 3.5 adapter kit.
I hope I was able to help you a little anyway.
So the 10MB/s that have been suppressed probably won't cut it either. The SATA connection stops at 600MB/s anyway. If you then look at the NVMe models that achieve ~3,000MB/s...