8GB with even a several years old CPU should be perfectly usable. SSD is absolutely required though. No number of cores and gigs will compensate for the lack of ssd.
The interface is unrelated to the IOPS you get out of a hard drive. 3Gbps SATA II has no trouble delivering far more than the ~200 IOPS a 7200RPM hard drive is capable of.
Not a fan of the UI changes, or the advertising. If I didn't buy Office 365 every other day for the last year, what are the odds your popup will get me to buy today?
Windows 10 cannot work on a hard drive?
In a way, it makes sense: when my father upgraded from Seven to W10, W10 never worked properly and killed the hard drive in a matter of 3 days.
I fully agree with you, though. An SSD this day and age is mandatory.