I do have some information for several of the Edwards that you have posted.  Both Allen T. Edwards (living with Pleasant Howell in 1850) & Floyd W. (Webb) Edwards (m. Harriet Cannaday), were the s/o Joseph H. & Elizabeth Howell Edwards.   You have Floyd listed as the s/o Joseph H. & Martha Hancock Edwards; however I'm reasonably certain that he was the s/o Joseph's first wife, Elizabeth Howell who he m. in 1827 in Montgomery County, VA.  Joseph m. 2) 1840 Patrick County, VA to Martha Hancock.  Since Floyd was born in 1833, it would seem that he was Elizabeth's son.  Elizabeth Howell was the d/o Benjamin & Elizabeth Kendall Howell of Floyd County, VA.  Her sister, Nancy Howell m. 1832 Floyd County, VA to Lewis Edwards, brother of Joseph H. Edwards - they were my ancestors. 

I'm sending you some information on Joseph H. Edwards' family, so you can have the information that Allen & Floyd were the s/o Joseph H. & Elizabeth Howell Edwards.  I believe that both Allen & Floyd moved from Patrick County to Floyd County to live near their Howell relatives.  Pleasant Howell who Allen was living with in 1850 was their mother's brother. 

1840 Patrick County, VA Census:  Joseph H. Edwards 1 m. 0-5, 2 m. 5-10, 1 m. 30-40, 1 f. 5-10

1850 Patrick County, VA Census:  Southern District, pgs. 369-369a
287 304  Edwards    Joseph H.        47  M  VA    Farmer    $1,500
              Edwards    Martha            36  F   VA
              Edwards    Allen T.           20  M   VA    Clerk
              Edwards    Floyd              18  M   VA    Laborer                    
              Edwards    Susan E.        16   F   VA                                  
              Edwards    Larkin             13   M  VA                                
              Edwards    Franklin            7   M  VA
              Edwards    Luester             5   F   VA
              Edwards    Albert               4   M   VA
              Edwards    Brice W.           3   M   VA
              Edwards    Lewis           3/12   M   VA

1860 Patrick County, VA Census:  DIVISION:  North  PAGE NO:  885 REFERENCE:  Round Meadow,  June 27th, 1860
 95   97  Edwards      Joseph         56   M      5,000     6,000
             Edwards      Martha         44   F
             Edwards      John F.        17   M
             Edwards      Eliza            16   F
             Edwards      Albot            14   M
             Edwards      Brice W.       12   M 
             Edwards      Florance         8   F
             Edwards      Nancy A.        6   F
             Edwards      Josephine       3   F

As for the other Edwards living in Floyd County, VA - they were most likely descendants of Benjamin Edwards b. 1758; d. 1844 Floyd County, VA.   At one time, I thought he might have been my Edwards ancestor (he is not), so have information on him.  He served in the Revolutionary War & received a pension while residing in Floyd County, VA (but he is not on the American Revolution Plaque at the Floyd County Court House).  I have no proof of who were his children, but would suspect that Jesse & William could have been possible sons.  According to the 1810 Franklin County, VA Census, he had 2 sons ages 10-16 & in 1820 he had 1 m. 0-10 & 1 m. 16-26 in his household.  If you are interested in any further information on Benjamin Edwards, please let me know.