my wife went split op and encountered a few problems.
At the end of basic training, you are in decent shape. You are also use to doing military PT. In the year my wife took off, she remained in good shape by running but struggled upon entering AIT. She also got use to being a civilian again and had problems getting back into the "military mind set."
Another thing about doing basic and AIT in one shot is the friend factor. You will have friends in basic that will follow you to AIT. If you are OCET, where you do basic and AIT with the same bunch of soldiers, you will remain with familiar company.
About the college bit. If you go to basic and AIT (assuming your job's AIT is less than 10 weeks) in the very beginning of summer, you will finish AIT before college starts in JAN.
From a person who delayed college for 4 years for military service, I do not regret it one bit. College looks a little different when you take some time off. You will only laugh at the ignorance of the 18 yearold freshmen