Since no one has actually attempted to answer any part of your question....

Here are some figures.

18.4c/gallon Federal exise tax on gasoline (24.4c on diesel)
27.3c state fuel tax in Nebraska (check your state here http://www.nebraskagasprices.com/tax_info.aspx )
42 gallons in a barrel of oil,  price per barrel today is $96.28 or $2.29 per gallon
Spot price of Ethanol by state: ($2.69 Nebraska)http://www.dtnprogressivefarmer.com/dtnag/common/link.do;jsessionid=214544585E04EE1BF2C6BC794EBB2E5C.agfreejvm1?symbolicName=RENEWABLE_FUELS_PAGE_FREE
One bushel of corn can make 2.7 gallons of ethanol (plus byproducts) so every gallon of ethanol has .37 bushels of corn in it.

So to answer your question about $4.00 gas/10% ethanol blend,
$.457 or 11.4% goes to government
$2.06 or 51.5% goes to the crude oil production and transportation (1/3 of this for oil well royalties?) (I know crude isn't pure gas)
$.269 or 6.7% goes to ethanol producers who have purchased .037 bushels of corn for every gallon of final blended gasoline or  $.29 going to the farmer who sold at friday's close of $8.01
$1.21 or 30.4% goes to refining, distributors and retail gas stations.

I can only speak to a stripper oil well I know something personally about that recieves 1/3 of production as royalties and the operator recieves 2/3rds.

At $8.01 per bushel, it looks like the Corn farmer's share of the gasoline dollar is larger than the Ethanol Plant's revenue on ethanol by $.02  They must make up the difference with byproducts or from farmers who sold cheaper than $8.01 (nearly everone lol)

A farmers share of $4.00 gasoline/ 10% ethanol blend when corn is $8.01 is 14.5 cents per gallon or 3.6% and the farmland owner's share is the same (assuming a 50/50 share)