[Imports] delete unused nodes?

[Apollinaris Schoell]

during cleanup of some broken imports I discovered there are tons of unused nodes mainly from broken imports
started to extract them from a planet file

criteria I have used
- not used in a way or relation
- no tags or only tag is created_by

result: 1.7mio unused nodes

any reasons for keeping them? otherwise I will start to delete them over time.
I think it's save to upload because server does version checking and will reject 
upload will fail for all nodes which have been changed between planet dump and try to delete on server
upload will fail for nodes merged into a way/relation after planet dump
ongoing imports during planet dump will all be finished adding ways/relations before this deletion happens if I wait a couple of days

anything missing?