I will borrow over the long term 30 to 50 years it's common practice
Also had we had rich enough owners they could gift capital to the club that's pretty much what has happened at city. But failing that long term borrowing it's not normal practice to fund long term investments over short term income.
Not sure you can borrow over 30-50 years with our balance sheet which is in negative equity mind you and lending institutions being too careful these days. Even if we could, that would probably mean 20-25m in interest and capital repayment. For a club that has been losing money for the last few years and just going to make money now, if 20-25m is some additional expense, even with naming rights, we will struggle and probably become a selling club as Arsenal have been while they were paying for the Emirates. That would then mean no CL and less EPL money, probably less ticket sales, thus less revenues.
We will have a very nice looking, brand new stadium but probably in the middle of the table with no need to expand further. Your plan is completely flawed in my books, trying to sort the long term but putting a bullet in the short term. What you don't seem to understand is that if the short term is not sorted, the long term will be crap. Do the maths as an accountant and let me know if you see anything better.
Now if you want a gift of 400m from FSG, that's another matter and I don't know who would give such a gift to LFC.