Let's see... took me a bit of time to dig up but I found the old topic...
http://slickproductions.org/forum/index.php?topic=1863.msg19427#msg19427Now what you're looking to do should be easily done.
Your first request is easy enough, as I said in the topic there is a table that the game looks at to check how to use in a byte.
BF (-40) is normally used to heal Petrify, now if you wanted it to heal Toad, Mini, and Pig as well you would change BF (-40) to... let's see...
Pig is 8, Mini is 10, and Toad is 20. So BF should have 38 subtracted from it which is... 87, if I'm not mistaken here that should clear those statuses. Granted you could replace this over the DF, put 87 and get the same result, which would work for you since you want to change that item.
Your second request is the same vein. Poison - 1, Blind is 2, Mute is 4. So you just put F8 in place of EF and you're good to go.
BF (-40 getting rid of Petrify) FF - ?? DF (-20 getting rid of Toad) FF - ?? EF (-10 getting rid of Small.) FF - ?? F7 (-8 getting rid of Pig) FF FB (-4 getting rid of Mute) FF FD (-2 getting rid of Darkness) FF FE (-1 Getting rid of Poison) - FF FF (getting rid of All Statuses) - Just search for those values in ROM and you should find it.
Your third request would require a lot of new coding and wouldn't work At All in the status healing items, since the status healing items themselves all run the same code, but look in this small table (above) to remove status.
As a side note, isn't PickMeUp the name of the reviving item in Super Mario RPG?