I am not sure there is enough information given to give you an answer, or even what you are asking.
The title suggests you want to get into the firewood business professionally, but the tools, methods, and skill set, show a homeowner-type situation.
If you want to get into selling firewood to others, I don't think what you have is going to work very well. The equipment is non-professional and will quickly fail because it is not designed to be subjected to repeated use. A few cords of firewood per year for your own use, yes, but not cord upon cord of wood to sell to others. That sort of mind set would have to carry over into your methods of retrieving the wood which is unproductive to say the least. In trying to compete in a firewood market that is volume based, you would be spending a lot of your time getting very little in return comparatively. There are a lot of hidden costs in producing firewood professionally that quickly become apparent when getting into the market.
But if you asking if it is worth it for a homeowner to produce their own firewood, then by all means YES! The figures have always backed that up. I have looked at other ways to heat my home, but always come back to wood heat because I can produce enough firewood to heat my home in only a few days time.
Travis makes many good points. With your equipment, do it for your self and enjoy doing it. It’s often cheaper, when you cost your time and wear on equipment to buy in processed logs, and even then you have to stack and season them. Wood is very hard on machines, it wrecks everything. Secondhand woodland machinery is low cost, because it’s often at the end of its life. If you want to deliver firewood to people and make enough to live on, yoiu will probably have to buy in trees by the load, then use a processor to produce the logs. Any other way will mean you are worn out as well as the equipment.
From your figures it looks like you can produce 3.4 cuft/hr. If you are trying to run a business you need to think of £40 an hour in the UK, so I will be generous and say you need $30 an hour in the US. That means roughly $10/cuft. That’s a couple of net bags of logs. That’s a lot of work given 14 hour days and two of you.
Next is the risks. According to your sound track it seems you don’t have much in the way of safety gear. That’s possily ok when you start fresh in the morning, with perfect weather, and well behaved machinery. The problems arises when the weather is not good, and you get tired, and the machinery is being a pain. Then accidents happen.
A good example at 7mim 40s
This a tame one, plenty of gore available on youtube if anyone needs convincing. A guy I knew on another forum got caught when cross cutting at home. The saw kicked back and got his throat. He died. It can happen to anyone. Is it worth the risk?