which function would be the most rewarding: Te? and second and third?
Well it's more complex than that......when you look at the functions in isolation Te undoubtedly has the most benefit, but combining functions produces different synergies
eg. I personally think uber strong Te + uber strong Ni is the ultimate path to El Dorado, but Ni in and of itself is not exactly as much of a money making machine as Te is...nonetheless Ni is like a synergistic function....when combined with uber strong Te, it boosts Te's efficiency by a factor of 10 which is why that combo is the ultimate recipe....when combined with uber strong Fe, though, the effect is completely different...it instead boosts Fe's interpersonal intelligence by a factor of 10, which is why ENFJ is the most charismatic type of them all....nonetheless, ENFJs aren't exactly famous for being rich either...
Ne can be quite rewarding when you channel it to develop new products that has never been conquered before, which is an area where millionaires are made, especially when you combine it with Ti (so this is an area where ENTPs can potentially shine), though of course the risk is still high....but of course the drawback is that it often makes you slack off (hence the whole millionaire thing may never even happen due to lack of follow through)
ESTPs also typically make the best salespeople since they're extroverted, T enough to actually focus on profit, and yet have tertiary Fe so they can get into other people's shoes and actually detect what they want....being sensor helps them relate to the majority of population as well so they speak in the same language with the sensor majority (which is typically the target market)....