Getting the abs = fat loss. If youre only focusing on primarily cardio and just 2 days of some hiit, well by the time you see it, you'll look pretty skinny and small tbh. Muscle is metabolically expensive to maintain. When on deficit, your body will prioritize to get rid of it first, unless you give it a reason to keep it (hence resistance training is recommended during cutting)

Instead of 3 days jog and 2 days hiit (not sure how long and intense), id focus on 3 days resistance training and 2 days jog (why not 3, just do the cardio after). Increase the protein intake and track the calories. You'll see much better result imo

Depends on what type of workouts youre planning to do. You wanna go to the gym? Or just following standard home bodyweight workouts. Personally i dont do any ab workouts and the abs appears just fine.

If you go to the gym, simply focusing on core lifts, squat, deadlifts, bench press, rows with decent intensity and progressive overload and finishing with 10 mins of any random ab workout is more than enough to build the ab muscle.

If at home, usual pushup planks pullups, crunches and mountain climbers I guess? Short interval sprints will help as well.

Depends really on what kind of physique you're aiming for in the end.