I'm not able to answer all of your questions, but i can answer the Daniel Richardson confusion. If you look at 1850 Campbell CO, TN census you'll find TWO Daniel Richardson 's living 4 farms apart .. One is Daniel C Richardson married to Mary., age 32.#225. That puts the age in line with Mary Wilhoit marrying Daniel Richardson, as Mary Wilhoit was b ca 1820. I usually look within a + or - 5years on birth dates, as they can be didn't all ways know exact date they were born and it can differ on each census , too.
The other Daniel Richardson #229 is married to an Elizabeth , and their ages are 48 and they have a son John age 11., so 1839, which is the DOB for your john Hutson Richardson.
As for the Sarah Vinsant that married George Vinsant, That George on the profile is too old to be Sarah Elizabeth Wilhoit husband as listed. She would have been 8 years old when married.
Yes it is believed Simeon Wilhoit/Willhite had a daughter Sarah, Hope this helps
PS Some also have an Elizabeth born to Simeon Wilhoit/Willhite in 1804, just to throw some more confusion on the mix.