If I edit a dng and then load the dng in LR 4 will LR 4 recognize my edits? Will LR 4 corrupt the dng?
Yes your edits will be recognized by Lr 4 if you export the edited DNG's from LrCC and then import them back in Lr version 4.
Check Compatibility settings while exporting the DNG's
Edits are saved in Lr CC catalog which cannot be accessed by Previous versions of Lightroom(1-5). So export the edited image and then re-import them in Lightroom 4.
Hope that helps.
Some edit functions that exist in LR CC will not be recognized by LR 4 if you transfer it by DNG file. Which edits will not be recognized? The ones that did not exist in LR 4.
If you export a TIF and then import the TIF into LR 4, all of your edits will be there, baked into the TIF file.
Thank you all