They are easily removed. By using only center, top or bottom hits on the cue ball, most positions on the table can be reached by the cue ball after pocketing the object ball. If you practice these shots, and do not achieve similar results, make sure you are not cheating the pocket. Also, different cue sticks can produce more or less spin, depending on the condition of the tip. Just pay attention to where you hit the cue, and how the cue ball reacts off the rail in order to understand the dynamics.
All strokes are near medium-hard.
But, notice the hits shown on the cue balls. Additionally, the rebound angles off the rail are opened up. For me, and many others, inside english is like the Knight on a chess board. It is a marvelous weapon but takes longer to master. Inside english also induces more spin and directional throw on the object ball, which requires more aiming compensations.