Load Factor & Profitability
Load Factor is a factor of Price (hence Demand) and Equipment capacity (hence supply).
To aim for 60% load factor seems risky to me, either your prices are too high or your planned aircraft is too big.
As for calculating Profitability this is an area of smoke and mirrors so a lot depends on who you are talking to. The taxman, your bank, an accountant or your wife.
Your wife may quite rightly ask whether you are making an Economic profit on your own time. This is a very important question and one that others will not be too interested in.
Bon Chance