The interesting thing about businesswoman Lily I did not realize until I watched some 1989 episodes a few years ago is that the transition toward Lily caring more about business started in Martha's last months in the role. Lucinda began to find more of a place for her at Walsh. I know Martha did not like business stories, but then, Heather's Lily was only heavy in business for about a year or a year and a half before they began focusing more on Lily wanting a domestic life. I think Heather's colder, steelier persona and the early memories of her at A&M, crossing swords with Emily and Sean Baxter make it seem like she was more involved in business than she really was.
I agree that Holden was more interesting in a cold corporate world than on the farm. Marland himself decided, presumably with what Hensley wanted too, to make the character colder with the brain damage story. Unfortunately, this thread was lost after Marland died (and may have been lost even if he'd lived) - Holden was still treated as a leading man we were supposed to root for, even as he went around being a self-righteous prick and a deadbeat dad.
I never liked the relationship and I wanted more for Heather's Lily - I remember enjoying her with Linc. I do wonder if Marland reunited them in that period primarily for plot reasons. The show got a hell of a lot of story - big, big story - for years based on their reunion (Angel's breakdown, the Aaron saga, Holden's brain damage, etc.). They probably had more heavy story which impacted the whole of the show in that period than they ever did again.
Oh if you had known me around 1993 or 1994 I'd be in your ear all day on that subject, believe me. I do think he improved, or at least became more at ease, after his 1997 return. I don't think he was ever comfortable or happy in the role until then (as shown by him leaving twice - and probably his messier personal life as well).