At present i want to design simple VF (nor vector drive)

With the number of motors I have seen smoke using not so simple inverters set up wrong, I doubt you can get by with a "simple" VF.

For instance you will need skip ranges or the whole darn thing is going to shake apart.

You may be able to get by without softstart, but that is probably going to cut the life of your motor, applying the same voltage to a motor regardless of frequency will kill it rapidly.

Be very careful what you "simplify"

Erik