1. I found the All TMs and HMs code on gamefaqs, though I don't know the link
2. The all items code is split into 5 codes on Heartgold Neoseeker
3. the walk thru walls code is:
94000130 FCFD0200
1205DAA2 00000200
D2000000 00000000
94000130 FCFD0100
1205DAA2 00001C20
D2000000 00000000
I tested the walk thru walls code and it works.