An elite runner can cover 18 to 19 miles in 2 hours so I would say that 2 hours is definetly enough for a 10k.
Two longer runs and two workouts is perfect! I would suggest one long run of 2 or more hours and another medium long run of 90 to 105 minutes. Although I would treat the longer long run as workout, having an easy day before and after.
Also, two workouts is great, however, the type of workout you do will depend on what specific race you are training for. The workouts for a marathon are very different than a 10k. For example, I would do lots of steady state runs if I am training for a marathon as opposed to 5k-10k pace intervals if I was training for a 10k.
Here is a sample week for 10k-half marathon training
Tue: Tempo Workout (tempo run or intervals)
Wed: Medium long run 12-14 miles
Fri: Workout (5-10k pace intervals)
Sun: Long run 15-18 miles (moderate pace with hill sprints at the end)
Here is a sample week for marathon training
Tue: Steady State Run (basically a marathon pace run)
Wed: Medium long run 14-16 miles
Fri: Tempo Workout (tempo run or intervals)
Sun: Long run 16-22 miles (either all at a moderate pace or add some steady state running at the end a few times a month to mimic what a marathon feels like. If the later go at least two easy days afterwards. Build up )