I Think here you are factually incorrect, although I do get your point. Their entire marine force may be wiped out, but by only comitting 2500 they cant really take massive casualties after WW2 standards.# 3 is an impossibility under historic circumstances. It is unlikely, although not impossible, that the Japanese could have wiped out the American carrier force, but actually TAKING the Island? Even if they managed it it would have made Tarawa look like an Administrative Landing. The Japanese had not practices a landing in advance, despite the fact that they had two SEPARATE commands (a SNLF detachment and a reinforced under the command of Col. Kiyonao Ichiki (of Guadalcanal infamy) totaling only 2,500 men to invade two separate islets (one of which had a heavy platoon of light tanks that the Japanese didn't even know existed) defended by 3,500 troops, mostly Marines (including a Raider battalion) in prepared defensive positions. There was NO floarting reserve to provide support for the IJA/SNLF except construction laborers.
The Japanese plan called for a brief bombardment by a cruiser division (4 CA) followed by a landing at dawn. American defenses include four 7"/45 guns (secondary guns from the Mississippi class of pre-dred BB class) that had the capacity to punch straight through the belt of the Mogami and her sisters, along with five 5"/51 coastal defense guns.
The Americans invaded Tarawa (defended by ~2,600 troops and 2,000 construction laborers) with 18,000 Marines supported by 6 CV, 5 CVL, and 6 CVE (with many of the pilots Marines who have actual CAS training and the other Navy pilots have done considerable practice against land targets), 12 BB, 8 CA, 4 CL, 66 DD. The American landing force took 3,100 casualties (1,009 KIA) depsite being directly supported by more battleships than the Japanese navy possessed, better than double the carrier aircraft carried by the Kido Butai at Midway, etc.
Zero chance the Japanese don't take massive casualties, even if the manage to win the m]land battle (IMO the chances of that are under 30%).
Sorry, couldnt resist.