The Kazon mothership would have destroyed Voyager had Chakotay not taken action, with no weapons array or backup close by they were out of options. Janeway pleaded with the Caretaker to send them home, though knowing what was coming and the damage it caused first time they could have reinforced the ship for the journey home and ensured the crews were kept safe. It was her decision to destroy the Array (with weapons that were magically back online), but it would have been destroyed even without the Kazon collision. Taking the action she did was a huge violation of the Prime Directive, but when weighing up the lives of 150-ish with thousands (if not millions) she could have been said to have done the most compassionate thing. Getting Voyager trapped in the DQ is no one's fault, but rather a random convergence of incidents that had only a finite number of outcomes, none of which were exactly very favourable. I get why she blames herself at times though, as it is something that she could feel guilty about, even though she did it for good reasons.
Do I have to watch the pilot again? From memory... The initial attack force was a City Ship and two Shuttles. Chokotay destroyed the city ship, at the expense of the Val Jean. All Voyager had to fight Two shuttles. Janeway was not afraid of the two shuttles, Caretaker had convinced her that the Kazon were going to steal the Ocampa's water. Just listen to that. Not kill, not eat, not enslave... But "steal their water". The Kazon had no interest in the Ocampa whatsoever other than their water WHICH WAS ONLY VALUABLE ON OCAMPA and would have only been used in the refinery on Ocampa. She was afraid of reinforcements. Because this was Kazon space where the Kazon live, so of course they could get 10 more city ships there in under an hour. Ignorant of truefacts Janeway was right to be paranoid because of baseless assumptions. But from what we know about the kazon, reinforcements from their own sect or another sect would just lead to infighting and powershifts since weakness is not tolerated. What you're all still forgetting is that the array is a weapon. It had disruptors that could target the Ocampan city from a couple light years away, and he could have just as easily chosen to target the Kazon living on Ocampa instead, but Caretaker is a deush. Meanwhile they could use the tractor beam that dragged them from the Alpha quadrant to crush their enemies. Safely plotting a course home may take "many hours" but I think crushing a Kazon City Ship is just a matter of randomly thumping the control panels with abandon. Besides those city ships are cities. 22 times the mass of Voyager means that any one of them is containing 10's of thousands of civilians, whatever mutual defence pacts they have in effect, it can't be worth losing another City ship over, unless your next step was to open fire on Jabin, take the array, and take Ocampa.
Really, why couldn't Janeway have used the displacement wave to send the Array back to the Alpha Quadrant with them? The displacement wave obviously didn't originate from any part of the Array, or else there would have been 70,000 light years worth of planets, debris and ships littered around the Array from the origin point to its interception with Voyager in the Badlands. Just set the thing to activate a wave 1,000 kilometers off to the side of the Array so that it picks up said Array and Voyager, then voila! No Prime Directive violations, no Kazon overtaking the Array, and Voyager's back in the Alpha Quadrant with the Maquis getting prosecuted to the fullest extent of the law.
The displacement wave was part of the super tractor beam which Tuvok found the controls to on the array and figured out how to work it in a matter of seconds. The displacement wave was probably a secondary effect or a scanning system so that Caretaker knew what he was grabbing, since Voyager was dragged to the DQ trillions and trillions of times faster than the wave was moving which Voyager's crew could see with their naked eye. If the super tractor beam was not on the Array, then either either our heroes are morons or they would have gone home. Besides the "displacement wave/super" tractor beam was discriminate becuase when it took Chakotay, it didn't take the Cardassians who were right beside the Val Jean when the Cardassian's were nabbed.