what does this say about his attitude toward snowball and his inventions? what does this say about napoleon in general?

What do you mean by "this say". Please specify so I can give you accurate response.

Thanks

when he urinates on snowballs complicated plans for the windmill

It shows us that Napoleon has no interest in helping the welfare and fortunes of the animals. To Napoleon, the windmill represents Snowball's vision hence he urinates on it. Napoleon is all about his own peer and ego. It is interesting to note that when Snowball is chased off, the windmill becomes Napoleon's idea.