Hi,
Thank you very much for your offer and your kind words, I’m working alone so I’m completely overloaded with work for months. For WordPress related work I recommend wpkraken.io – it’s a fairly new service, by a team of codecanyon/themeforest authors, specialized in WordPress. In case you want to outsorce some customizations, they might worth asking.
As for the code
That code does no exclusions whatsoever, it’s only a visual ‘fix’ for rounding up the values. But, there is a way to check the stock status of the products (stored in a different custom field), and exclude them, check on this knowledge-base article: Showing in-stock products only