Finally, when applying discount factors, where do you intend to get your discount numbers? For a company with existing debt and equity capital you can calculate WACC and use that. For a startup company you need to figure out a risk_adjusted cost of capital that makes sense. Usually this is not just a risk_free rate which only the largest companies in the world have access to. It's probably something higher.
In earlier times, accounting was done manually. With the coming of computers and increased technological advancement, accounting is slowly transferring from manual to mechanical dependence. It saves a lot of time. Earlier, hours were spent on drawing the basic design of sheets and other financial instruments. But now, you have access to balance sheet templates, which have readymade categories and spaces for computing. Now, one just has to enter the amounts manually and all other things are done mechanically.