This assessment is my personal guess at how much danger is involved with a project such as this. I'll tell you right now that I am only an amateur hobbyist and that you should seek a more professional opinion.
There are several types of danger involved. They lead to electrocution, radiation and mechanical injury. When you are trying a project out for the first time you do not think too much of safety because of the excitement of the project. When you are trying a project out after many modifications you do not think too much of safety because you tend to overlook it. Many inventors have been killed by their inventions. Many.
The electrocution danger is the greatest. High voltage electricity does not always do what we think it should. It finds ways around barriers. It finds flaws that we overlook because we think in emotional ways. You can't see it but it definantly sees you. The electricity will take a long path across bridges that you don't even recognize and hit you when you least expect it. You don't get a second chance if the voltage is high enough.
The second greatest danger is mechanical injury. Mechanical devices tend to operate for a long time and then disintegrate after you have become confidant that they are safe and reliable. As simple as the motor/alternator may seem it is all you need have as a personal meat grinder. The belt can easily break, wrap around an axle and then reach out like a whip and cut you very badly.
The third greatest danger is of RF radiation. A transmitter is like an open air microwave oven. It will cook anything near to it. This is true even for low frequencies. When you build one and work on it there is a tendency to sit there and watch it operate while trying to think about a problem it may have. While you're thinking it is cooking (you). You eyes cook fairly easily. I suspect that is why so many old RF engineers have thick glasses after glaucoma surgery. Sterility and cancer are the second and third side effects of radiation exposure. These are even caused by equipment that does not transmit. Always think of power levels involved and not just the frequency used.
There are other non fatal dangers to consider also. If you radiate RF energy there are many accidents that can happen because we live in a fragile world. It is fairly easy to knock out TVs, telephones and even computers with a fairly small amount of RF energy. Ham radio operators have always been in trouble for this. If you disrupt other peoples lives in this way you can expect them to come looking for you and to be quite hostile when they find you. If it is the FCC who finds you, you can also expect legal prosecution.
Always put safety first. It's not easy. Do it.