So I have tried Inserting and also importing a large sketchup file and I always have a great deal of blocks in Rhino. I don’t need any blocks. In the process of inserting the file I turned Off the blocks option and selected individual items. Anyway to Not have all of the Blocks? 
Yep… it can be a nuisance. ExplodeBlock, then Purge > UnusedBlockDefinitions = Yes.
-Pascal