Would the low cost carriers have forced them out? Yes - Gill couldn't have matched their fares or had the brand recognition (outside the likes of us, nobody knew Gill existed - I know, I twisted those arms...)
Would the low cost carriers have even come to Newcastle if Gill were still here as Go only came once Gill had abandoned the Stansted route? Yes, see above;
Would Gill be flying 737s as they dreamed and become a Jet2 affair? Don't know, but probably not - they didn't have a Channel Express behind them
Would they have swallowed up by the likes of flybe? Probably...
Would Newcastle be a better position or not? I hope so, but probably not
Great questions - is it only 10 years????