1) Can I spray the bees or hire someone to spray?
2) Can I seal the Bees up in the wall?
When you spray the bees, more than 90% of the time, the spray will not kill the honey bees off. Usually when spraying the company spraying will only spray the outer comb of the bees. Considering there's usually a minimum amount of 6 combs, you are really only killing 1/6 of the bees. And the honey bees will be able to get back that 1/6 within a few weeks. If you end up killing the queen, you will see a reduce population for about 4 weeks and once a new queen emerges, the numbers will be right up to where they were before. If you somehow end up killing the entire hive 5% chance, you will actually have more problems then having honey bees. Uncapped honey will spoil within a couple of weeks and with no one to defend the honey, roaches, snakes and rodents will welcome themselves to their new living space.
More than likely the bees will find a way out. Usually ended up taking the route into your house. Bees are not the only thing you should be worried about, the honey will spoil and cause more rodents than you can even think of. If they do end up staying in the wall and dying off, 30,000-50,000 bees is equivalent to having a small cat/dog die in your wall (smell, etc).
This is one of the most mistaken questions. Yes, we keep the bees, but beekeeping is not a full time job and often is hard just to make ends meet. In recent years beekeepers are trying their best to hang onto everything they have. Most beekeepers are facing 40-50% hive losses a year. There are a ton of expenses that go into keeping hives. During extractions and cut-outs, some of the bees will die as well due to heat, stress, and handling.