On the front tire deal, we have 2 cars here that currently run pizza cutters on the front. 4" wheels on both of them. They are driven fairly regularly and have been this way for many years.
One is running the M/T 28x6 street radial tire.
I can say they drive well enough, turn and stop fine in normal type driving. Even okay on the twisty mountain roads around here. A couple of panic stops in the past has locked up the front tires but you have to jump on the brakes pretty hard to do that. Locking up the rear on these cars might be more of a challenge anyway because we run drag radials on them 100% of the time and they are grippy. So may not be a fair comparison. Thousands of street miles like this though and no complaints. These cars aren't something we go racing through the mountains with on the twisty roads either though.
My daily driver for years was a 71 nova and I had made 4 inch chevy rally wheels back before they were being produced and ran 165/15 VW tires on it. Drove that car for several years without problems. Before that I daily drove a 56 nomad with manual steer and manual drum brakes that handled like a school bus so you kind of get used to extra braking distances and slowing for curves, which is probably why skinny front tires don't bother me.