If you enjoy rollerblading, then rollerblade away!  Keep in mind that due to the push technique usually associated with roller-blading that you’ll use the muscles in your hips and lateral or outside portion of the legs.  My question is, how do you know you have inner leg muscle weakness?  Have you tried smashing your calves to assist in decreasing the stiffness that you notice in them when you wake up?  Sounds like you’re off to a great start in creating an arch and torque for yourself.  Keep it up!