Let's say I have to delete the acquisition and depreciation history for 1 fixed asset. Will there be any impact on other fixed assets if I run depreciation again just to generate the depreciation history for this 1 asset?

should be fine, but bear in mind undoing a month of depreciation is not as simple as just deleting a depreciation history record in Netsuite FAM. Also a few fields that need to be updated on the asset header