I think Tom seemed a little bit of a fish out of water at the start. He did have some mighty big wellies to step in to. As you mentioned not the best of actors and did over do it at times in the beginning. Yet I do feel that he settled into the role eventually. Really liked his money generating schemes and working with Auntie and Smiler.
I feel it must have been a challenge at the start for anyone. Dealing with his Dad passing away and then working with the people that his Dad worked closely with for so many years. Being at Holmfirth and with the other actors had to of been a daily reminder of his Dad and that he passed on.
Will freely admit it took me a little to shine on to Tom. Am glad I stuck with him because he is a good character. A bit silly at times just like just like Smiler, Eli and the others
. Mrs. Avery did not fit as well I thought. Though I did like her more when they moved in next to Nora and both ladies would try to smarten up Tom. Agree that Avery's niece (?) was not a good match for the show.