Creating New Dialogs (and also BAMs and projectiles)

I've finally figured out how to use WeiDu to set up proper strings for spells, items, and critters, and also copy over files to the override folder. And I know how to use Near Infinity to create spells, items, critters, .2da files, and stores. But there are some things I don't get.

For one, I don't know how to create a completely new dialog from scratch and give it new strings. I've found tutorials for editing existing dialogs, and I can create custom dialogs with pre-existing strings, but I can't create a simple dialog to open a new store.

Less importantly, I'd like to learn how to create custom BAMs. I can copy BAMs from IWD2, and I can create my own image files, but I don't know how to get from BMP to BAM.

Finally, I have no idea how to create new projectiles. All I know is that getting them to work requires adding an IDS entry, which I don't know how to do. And I've no idea how to edit them.

Can anyone tell me how to do any of these things?