Round trip to Midway from Kauai is about 2,400 miles, so unless the plan is to land about 600 miles short of the runway, then the bomb load has to lighten up.
https://www.thisdayinaviation.com/tag/wright-cyclone-r-1820-97/
With a normal fuel load of 2,520 gallons (9,540 liters) the B-17F had a maximum range of 2,880 miles (4,635 kilometers). Carrying a 6,000 pound (2,722 kilogram) bomb load, the range was 1,300 miles (2,092 kilometers).
2520 (US) gallons is 15,687 lbs for 2880 miles. That 5.5 pounds of fuel per mile. A 6,000lbs bomb load drops the fuel carried to 9876lbs, which at 5.5 lbs per mile is good for 1,800 miles. To get 2400 miles would be a 2,676lbs bomb load, which is basically turning a heavy bomber into a medium bomber.
G4M Bettys with 1,800lbs bomb loads couldn't kick the US off Guadalcanal, so why would B-17's with 3,000lbs bomb loads succeed at Midway?
I wouldn't think Nimitz is going to let them keep the island so a submarine refuelling base in 1943 is probably beside the point. But, if the 1st USMC division is storming Midway in August, it didn't take Guadalcanal in August.
How many troops would you really? Midway is at the tail end of the Japanese supply lines what days sail from Pearl take a Marine Rgt get them some Amtracs and have them storm the Island under cover from the Battleships and Heavy cruisers why would you need a full division to cover an area of what 1200 square acres defended by how many men who are probably on the receiving end of a naval bombardment and aerial bomb loads for weeks. I don't think you will need the First MD