My goal was to take off from the surface of Kerbin and get to orbit, and I thought launching from the mountaintop felt better than Scott's similar solution of raising the craft up a few thousand metres up with launch clamps. I tried to stick to the same 'rules' that Manley gave himself in his video. An elevated launch site is practically essential for the mission, though I reckon it is theoretically possible to launch from sea level with a craft with many, many more parts.
I feel you regarding the computer struggles, and unfortunately I don't have much hope of playing KSP 2 when it rolls out given technical limitations. I don't think they're even planning on releasing it on Mac