You are wrong. Northern Jersey--Warren, Sussex, and western Passaic County, are all solid GOP territory. I would dare say the most conservative GOPers in the state come from Sussex County. We just sent Scott Garrett to the US Congress. In fact, according to the most recent census statistics, Sussex County is 4-1 GOP. Good people. Salt of the earth. NJ has high taxes/socialists because we have a lot of urban areas--blue zones. It's that simple. Urban areas=liberals.
Property taxes there are indeed insane. My aunt and uncle pay $12,000/year in South Orange (yup, 12 G's a year). It's so bad that two towns are trying to secede from their county, but the county will never let them go because they can steal far more money from them than they can get from the other towns.
Their taxes are high because they are in Essex County. They have to pay the social services and police and fire etc for Newark, Irvington, East Orange, Orange, etc. In other words, they share a county (and borders) with some of the worst ghettos in the state. Then again, people live in towns like S. Orange so that they can be closer to NYC in an affluent neighborhood. It's the price you pay for the life you choose.
If they raise the income tax, you might see a ton of people flock to PA, where the property tax is a flat 2.8%.
No you won't. PA doesn't have the jobs to support all those people. People live in high taxed areas of NJ like S. Orange, W. Orange, Montclair, Short Hills, etc so they can have a short trip to NYC, where the $$$ jobs are. You are not going to see a flood of affluent professionals to Scranton any time soon.