I have a large chesapeake bay retriever and he lived in an apartment for the first year and a half of his life with us. We're now in a house with a backyard. I won't lie...having a backyard makes things MUCH easier! But having a dog in an apartment is very doable and can actually have some very positive side effects. Apartment dogs are usually guaranteed lots of walks, socialization and exercise, so moving could be good for both you and your little guy!
I HIGHLY recommend frozen kongs! Chase gets half of his breakfast in a kong, mixed with plain yogourt and pulp from the juicer, with a little bit of bread and peanut butter to seal it shut. He LOVES them and is quite happy to spend 30 minutes emptying it out. I've read about dogs who can spend hours emptying out a kong, but I haven't yet figured out a combo that will take Chase that long. We also have a big hollow rubber ball with a small hole in it. You can fill the ball with kibble and the dog has to knock it around to get the kibble to fall out. Chase didn't really like it all that much, but I think it would be great for a small, active, high energy dog.
I don't have a small dog, so I can't give you any tips about barking, except that you might also want to set up a tape recorder to get an idea of when/how much your dog barks while you're gone. When he was a pup, Chase went through a stage where he'd bark while we were gone. Our neighbour told us that it was for hours and hours, but after tape recording it we found out that it was for about 15 minutes and that it started about 20 minutes after we left. Pretty annoying, no doubt, but definitely not hours and much less daunting for us to fix. We just got him a bigger kong so that it would take him a bit longer to empty, and give him a bit more time to acclimatize to us being gone.
We also left the radio on while we were gone and kept him confined in the bathroom when he was a puppy. When he got bigger, he graduated to the kitchen. Now, at 2 and a half, he has free run of the house.
Good walks in the morning and after work are a must. I would really recommend tiring the dog out in the morning. Make sure he's good and worn out. Short training sessions to keep his mind busy will help as well. A tired dog is a happy dog is a happy owner.
If finances allow it, a dog walker or a doggie daycare once or twice a week will also help.