Should I pursue becoming a USAF Officer (ALO) or a USMC Officer?

Reading you question narrative, it sounds to me like you want an opportunity to lead service members in the ground warfare environment. If that's the case, then my advice is to look seriously at the Army and Marine Corps. The Air Force and Navy have very few officer billets in which ground warfare is a primary mission.

Air Liaison Officers are most often rated officers (pilots, navigators, systems operators) who can bring air combat or air mobility expertise to their assigned ground forces units. To get there you would have to be commissioned, complete training as a pilot or other officer aircrew position, gain experience in an aircraft that either supports ground forces or provides air mobility. Then complete an air-ground operations course to familiarize you with the way the ground forces and air forces work together. This is a 5 to 8 year path.

The Army and Marines offer opportunities to lead troops in ground operations after a few months of OTS and officer advanced individual training. Time from commissioning to leadership opportunity, usually as a platoon leader, is less than a year.

It's also important to understand the Services assign different levels of importance to missions and positions in various MOS or AFSCs. (Major over-simplification follows.) The missions of the Army and Marine Corps are to fight and win the nation's wars on the ground. The Marines get there from the sea and air. The Army gets there from the ground, sea, and air. Consequently, officers in the combat arms of the Army and Marines (infantry, armor, artillery, etc.) often have higher promotion rates. The Navy is all about sea power. They operate surface and subsurface ships to control the ocean environment and launch strikes against sea and land targets. They have their own air force (Naval aviation) and their own army (the Marines). The Air Force mission is to fly, fight, and win. The key leadership positions normally go to pilots and other aircrew members who command and operate manned and unmanned air and space platforms. Non-flying officers can do well in the Air Force and often handle great responsibilities, but never serve in command of operational units taking the fight to the enemy.

I strongly recommend you talk with an officer recruiter from all 5 armed services. Spend some time researching the missions and functions of each service. Select the Service that is the closest match to what you think you want to do with your life. Also, understand which Service will give you the best deal in terms of accession date, potential credit for advanced education, and guarantees post-commissioning training or school.

As far as family life goes. The further from the front line your job, the more likely you are to be "home for dinner" every night. The front line officers in all services are subject to short-notice and extended deployments away from their families. This is often difficult for the spouse and more so when children are involved. The Air Force usually has the best on-base living quarters, recreational facilities, and shopping.

(Join to see) You are soon to be married, and children are always a possibility. What does your fiancée think about your joining the military? Have you had discussions with her about the amount of time that you would not be with her while in training, deployments, etc.?

If there is any question in your mind if you want to be a Marine Corps officer, of any kind, it may be best to go with the other service.