Hard disagree on Solo miscast leads and a leaden script no matter who the director was it was in trouble, especially considering the actor is not Harrison and they killed him like he was nothing in Force Awakens, way too late to make a prequel for a dead Han. Might as well have tried to sell dead Han toys.
As to moving the timeline from 3 to 2 years between films I do somewhat agree, but I also agree throwing out Lucas outline and then having no plan was a problem as well.
Solo was a lame idea from the jump, but it was one of a few projects that came with the sale, and something Kasdan wanted to write. An easy choice to make when you need a new film released each year.
I have trouble fully blaming Lucasfilm for these failings when we know Disney execs impose aggressive schedules. Bad decisions are often made in a hurry.