Basics (1) - S2-E26
Corrected entry: The Kazon attacks are concentrated on the Second Command processor and yet nobody checks what would happen if it fails. When the time comes to order the self destruct, everybody acts shocked that the Second Command Processor has a direct influence on the self destruct. This ignorance would not have been a major problem for any other Federation ship but in Voyager, the self destruct is activated as often as the phasers (especially in this season).
Basics (1) - S2-E26
Corrected entry: When Paris suggests to take a shuttle craft and contact the Talaxians, the Voyager momentarily slows down below a Kazon ship so that the shuttle can depart. This is probably the worst place you can imagine to launch a shuttle. During the whole space battle the Voyager was flying in loops around the Kazon carriers, literally. Which means she is a lot faster than her enemies. If you want to send a shuttle, wouldn't you go to a safe distance and then release the shuttle? Captain Janeway's choice would made sense if their engines were damaged but at that time, the impulse engines were functioning perfectly.
Correction: Janeway's hoping that the shuttle can sneak away without being seen. If she leaves the battle and comes back, the Kazon will know something's wrong and would search for it.
Correction: Voyagers crew believe that the Kazon are concentrating their fire at that spot is in order to drive the shields down without giving them time to recover (it's just a convenient spot like the deflector dish), they don't think they have the knowledge of the ship to knock out one of their last ditch defensive measures. Also it wasn't just the ships the Kazon man who blew himself up would have helped greatly to affect ships systems (including the self destruct).
The Voyager crew should have know that Kazon "loyal to no one" all having the same agenda was suspicious and more time should have been put into finding out why as they knew the processors were being targeted each time. Of course they knew enough about Voyager; they'd had Seska feeding them information for months (to say nothing of Michael Jonas before he was killed). Tieran's suicide only took out the weapons and defenses. However it should still have been possible to destroy Voyager by firing a phaser at the warp core as the Doctor was about to do in "Projections."