Another reason to keep him leashed is his propensity to hide under furniture (couch etc.) My knees can't stand crawling around on hard floors to catch him if he's needed for walks or feeding. Since he's not used to the walk routine yet, he doesn't rush to the door and get excited at the prospect of a walk, like Fifi does. When I call him he comes near but won't let me touch him. With a leash trailing behind him Harry is a lot easier to catch.
When it comes to sitting with me in the living room, I have to place Harry on the couch beside me, otherwise he just goes and hides under the couch. It helps that Fifi then comes and curls herself up between Harry and me. I think he may feel safer with Fifi there. He shudders and shakes while sitting with me, which makes me a bit sad. But I have to remind myself he's like a chihuahua - they don't always shake from fear or cold, sometimes they shake from excitement, wanting something, etc.
Today a small milestone. I had parked Harry on the couch beside me and went to get another cup of coffee. I expected him to be gone or in the process of taking off when I got back, but he had only moved over a bit on the couch. I moved him back to make room for me and he stayed.
Then a while later I went to the bathroom, which is right next to the bedroom.This time Harry followed me, and went straight into the bedroom and up on the bed! I guess he thought I was going to lie down for a nap again. When I went into the bedroom he jumped down and dove under the bed, but it wasn't hard (using the leash) to get him to come out and with me back to the living room.
I've been working on using Harry's name and getting him to associate certain words with good things. Like "good boy!" when he poos or pees outside, or "walkies!" when getting ready to go for a walk. He's starting to respond to his name more. The other stuff will take a bit of time. But I think Harry is a smart dog who wants to please, and will pick up on things quickly.
Now if I could only get him used to the cuckoo clock!