I think the only way to be sure the game, it`s not corrupt or damaged is buying the original disk if itºs avaiable or download it with a torrent application, although it may be not legal and might contain virus, old DOS virus will not affect modern systems, and some of them may contain the game without any crack.
A Crack utility can be used with them Neverlock or CrackAid for example.
The reason to do this is because some floppy disk may be too difficult and expensive to find and even if it's found it may contain sectors with errors.
The 8086 CPU can be up to 50% faster than the 8088, because the 8086 has 16 bit memory bus and the 8088 8-bits. notwithstanding both of them has 16-bit internally and 20 bits of memory directions.
As for EMS memory, it´s not a big problem for games developed for 8088/8086 XT because that games uses Conventional memory only.
The apllications that can use EMS memory are applications such as Lotus 1-2-3, Windows 2.0 and some disk caching utilities,such a PC-Kwick.
The games that require EMS memory such as Incredible Machine II and Black Thorne, requires at least an 80386.
This is because
1. Uses 386 real mode instructions
2. Requires some VCPI fuction (Virtual 8086 mode)
3. Uses an amount of registers not supported by any EMS board.
Support for EMS was added in Laser XT machines (in PCEM source and 86box)
I tested Manifest application included in QRAM 2.02 with LaserXT (added by Greatpsycho) and Award 286, which has an SCAT chipset.
And QEMM 9.0 with an 486 DX/2 66 mhz.
On Laser XT Manifest only sees the 64kb Page Frame. (There is 140kb of free UMB but it can not be mapped with EMS 3.2 hardware).
The EMM.SYS driver say '4.0' when loading, but it is 3.2 at hardware level, i discovered that because the OEMSTEST Program created by Douglas Boling show that 4.0 fuctions are not supported. Nevertheless this driver grants compatibility with Windows 2.0 and 2.11.
The Award 286 wich support the EMS 4.0, it also detects 384kb of the conventional memory as 'mappeable' (this means, this area can be copied back an forth the conventional to EMS memory and then from EMS to convetional, (this is called 'Large Page Frame'). And also 128kb of UMB can be used.
On the 486 QEMM can map nearly the entire 640kb area, and even map the smaller 4kb memory blocks can be used as UMB memory.
This is why the games that requires more than 64kb of EMS requires and 80386 and a software such as EMM386/QEMM/386MAX to run. It is faster because uses the 32 bits capabities of the CPU, can map device drivers in UMB memory, so more conventional memory is avaiable and no extra hardware is required.
There is a good book from 1992 that explains the difference between the EMS 3.2 and 4.0 memory boards, and the 'new' (for it´s day) memory magement capabilities of the 80386, it can emulate EMS memory using XMS, by enabling the V86 mode, in this mode the CPU intercepts real mode instructions and manage it inside the protected mode, solving the problem of the 286 which needed a reset to return to real mode from the protecetd mode.
Here is it https://archive.org/details/DOS_Beyond_640K_2nd_edition