Death Items = items in the Corridor of Death?
Idle = no job, with not even hauling? Or can I set up a few "Food Hauling Squads" (FHS) [nerd pun intended]?
EDIT: 5 pick became weapons, but I'm pretty sure there is a way to revert them into a digging implement.
Indeed, all items owned by your dead dwarves are likely to be collected by other dwarves if you have weapon/armor/clothes stockpiles. Remember you can mass select all the items in corridor with hotkeys: d -> b -> f? (c = reclaim, my guess is f for forbid, anyway, easy to find in that menu anyway)
Idle as in doing nothing at all except having some medical stats enabled, may want to consider setting one or two dwarves with some of the med skills if you have none (i.e add diagnosis profession to a random idler if you have no dwarf with diagnosis)
If you want to select someone who might be better at the job than another dwarf, check the wiki for which attributes are used and select a dwarf with relevant attributes (i.e
http://dwarffortresswiki.org/index.php/DF2012:Diagnostician = Analytical Ability,Memory,Intuition)
Removing the miners from the squad or making sure they're not active in the squads menu should be enough to make them go back to normal picks, either that or they work both ways without any input required.
I presume u managed to make it alone and don't need anyone to look at the save?