Later versions of Windows do not lack any of the accessibility features,
Really? Are you sure? Many vision impaired people have to fin-tune colors and font and contrast personally. The is no on-size-fits-all or anything even close. It looks like Microsoft got rid of the people that did accessibility for Windows XP.
I'd guess you are referring to the "Visual Effects" dialog? That was for customization, and wasn't intended to be used for ease-of-access. Win10 has several High Contrast Themes.
1. How do I enlarge the mouse mouse pointer?
By changing the Mouse Pointer Scheme.... Same way as you do on Windows XP:
Windows 8 and Later also adjust the size of the Mouse Pointer based on the current DPI Setting.
2. How do I find the find the mouse pointer? Hold the ctrl key? No.
"Show Location of Pointer when I press the CTRL Key". Again, setting is in the same place as it was on Windows XP. With Win10 you have to click the "Additional Settings" Option on the new Control Panel Interface to access the property pages.
3. How to I adjust font ans size of icon titles?
You can change your System DPI.
You could also use the built in capability to change Title Bar Text Sizes. From Windows Settings, System, Display, then "Advanced Display Settings" on the right pane. "Advanced Sizing of Text and other Items" is present in the "Related Settings" at the bottom:
Font sizes can go to 24 here, and that also scales with the system DPI.
4. How do I choose any color I want for the desktop.
I'm not sure what you mean by this. If you mean the background you can do that in the expected location- same area which allows you to set the background wallpaper, or in the Theme Settings.
Now, it looks like they reworked some of this area of Control Panel, so perhaps fully custom options aren't available anymore (I can't seem to find them), though you get a not-wholly awful selection of colours. Custom colors definitely are possible, as I have custom options set for both.
5. How do I make text black on modest color background?
On my Windows 10 I only only get text k on flame orange or sky blue. So I settled on the orange flame, but it brings on visual fatigue after about 30 min of use.
There are a few High Contrast options in the themes. These change the Title Bar appearance.
You can change the Accent Color as well, which can be set to change the title bar colour. (This used to have a fully custom option but seems they removed it- I'm set as a custom colour and yet can't find where I did so!)
I want to use Windows 10, but it has a disability. It is stupid.
It's certainly no harbinger of good design, with it's mishmash of old and new control panels, having to hop between them, and updates often shuffling things around; And the lack of the full Visual Effects dialog capabilities to customize pretty much everything down to specific fonts, colours, sizes, etc. is hardly great- We should be able to change things like the title bars font face or the font of Menus or whatever without resorting to registry hacks. Nonetheless, many of the things you were looking for were actually in the same place as they were in Windows XP; all that changes is the method of getting to those options. It's possible that many of these capabilities in Win10 were added since you last used it, as I remember the earlier releases being rather scant on many of the customization options.