Yup, the purpose of a game is to have fun, and if you have fun in a different way than "most people", that's absolutely fine. More power to you!
But you came here asking for help because you were stuck, so don't be surprised if you get well-worn (and generally well-working) advice that doesn't take your personal play style into account. People don't know that, after all, and they're sort of used to giving the same advice to all comers; it is after all "most efficient".
I agree that 6*ing Apothecary can't possibly be wrong. All the hype about him is 100% correct. He'll be my 2nd 6* on my alt account; he and Kael are a super team. The only reason he's not 6* on my main account is that I pulled him very late and already had a Doompriest (lucky!), who fits very well into several of my teams.
But by all means, make more 5*50s if that gives you joy. I did, and I haven't regretted it, and I have several 6*s now anyway; it just took me longer to get here. Like ToFu I found lots of use for them, especially in Faction Wars, which has made the game a whole lot less dull, and gained me materials that helped me with great gear and silver from the Forge. Also in Tag Arena where I farm gold bars that give me books and Ancient shards and energy. And I didn't feed my Shieldguard or Saurus from those earliest days either; they're sitting happily in the vault, fully booked, for when I have time to lavish some attention on them; I have to decide which one to make into my fast campaign farmer to free up my starter. I feed only champs who have no obvious other use to me; there is really no shortage of those from Mystery shards; Incubi drop on 12 like there's a factory cranking them out, and you ain't seen nothing yet if you haven't had four 4*40 Militant Sisters slicing their way through the Sewers of Arnoc just for the lolz.