You have to do all the red forest quests. The last one will get you to the army wharehouses. Bring something that has decent damage into the red forest. I suggest a tricked out shotgun or any of the weapon's that shoot the 9x39mm round. 5.56 and 7.62x39 are not going to cut it.
Not going to happen. That path is not there. To many anomalies. if you read some of the pda's you find it hints at that. Try to be neutral with Freedom and Duty your first trip there or you will get smoked.
Ah, save often or that happens. Normally I save every 5 min or so. Just a good habit. Reload a few of your older saves. Something before you went into that area and you should be fine. Also you have patched it to the latest right?