Front heavy vehicles do stop quicker because the front wheels are the ones doing the most breaking and when there's more percentage of the weight in front, they stick better.
They are indeed, more prone to rear end sticking out but on the other hand they will not understeer nearly as likely. This is a number one priority. Because if you understeer there's nothing to be done but hit the clutch and hope you get the traction back before the oncoming truck leaves you hanging at the electric wires. If you oversteer it's still possible to control the car so it's a more desirable possibility. And even if you fail, at least the truck won't crush you directly but just send you spinning(not that it's that much better then but it's something).
Lack of ABS does indeed cause immediate loss of traction in emergency braking and the braking power is not nearly as good in winter without it(considering it's not overly old ABS, those had some issues with braking power in winter). No arguments there, still, the car can be kept controllable without it.
More power does not mean you have less traction, in theory that is. In practice the amount of torque transferred with lower gears is ridiculously high so you'd need a starting gear with ratio that would spin the wheels slowly. Not going to happen unless you're driving a tractor. That leaves the clutch. You have it, it's meant to be used. Less gas is always a better option but in most torque heavy cars, like the mustang, it's going to slip even with little gas. So burn the clutch freely at winter. What the hell is a posi-traction? Googled, limited slip differential apparently. Oh, it will slip with most TCs too. Just look at the cars in traffic lights.
Actually, here people but weight in the bed to get more traction for RWD vehicles to not get stuck. Not to stop oversteer with front heavy vehicles. It does help it quite a lot, but the payoff isn't good enough when comparing issues with stopping time( and traction if it's a FWD).
I do think FWD cars are a lot better in winter than RWD ones. I just do not think the RWD ones are any less safe than the FWD ones are. They do take more practice to reach that point where they are as safe as the FWD ones though. But they can even be more safe due to the control of the rear with gas if you're good enough.