In regards to your second point, In June 1953 the Statistics and Accounting Branch published Army Battle Casualties and Nonbattle Deaths in World War II, Final Report 7 December 1941-31 December 1946, the most accurate report regarding U.S. Army casualties during WWII;

Line	Statistic	Number
1	Total [c]	936,259
2	Deaths among battle casualties	234,874
3	Killed in action [d]	192,798
4	Of those listed as killed in action; died of wounds and injuries [e]	26,762
5	Of those listed as killed in action; declared dead	6,058
6	Of those listed as killed in action; died of other causes (non-battle) [f]	9,256
7	Other battle casualties [g]	701,385
8	Of those listed as killed in action; killed in action	189,696
9	Wounded and injured in action	592,170
10	Of those wounded and injured in action, died of wounds and injuries overseas	26,225
11	Of those wounded and injured in action, returned to duty overseas	383,196
12	Of those wounded and injured in action, evacuated to the United States	182,749
13	Of those wounded and injured in action, died of wounds and injuries after being evacuated to the United States	84
14	Of those wounded and injured in action, returned to duty, discharged, etc.	182,665
15	Captured and interned	124,079
16	Of those captured and interned, killed in action	3,102
17	Of those captured and interned, died of wounds and injuries	453
18	Of those captured and interned, died of other causes (non-battle)	9,098
19	Of those captured and interned, returned to military control	111,426
20	Missing in action	30,314
21	Of those missing in action, declared dead	6,058
22	Of those missing in action, died of other causes (non-battle)	158
23	Of those missing in action, returned to duty	24,098

• [c] Sum of lines 8, 9, 15, and 20.
• [d] Sum of lines 8 and 16.
• [e] Sum of lines 10, 13, and 17.
• [f] Sum of lines 18 and 22. Excludes 83,400 non-battle deaths of persons not in a battle casualty status.
• [g] Sum of lines 11, 14, 19, and 23.