Does it matter whether or not there are any periods, commas, etc between your keywords? In doing a keyword search, I can't imagine how you would get some of the phrases into readable text without doing so. Ex: when searching the keyword "calf roping" there's a phrase that comes up..."rising stars calf roping". If you typed text "Neckbone is one of calf roping's rising stars. Calf roping is one of american's oldest, toughest sports." Thanks.
I have seen search results that place the punctuated phrase right alongside the continuous phrase, so I don't think it matters, as I think Google just sets aside punctuation. I try to use this to my advantage when writing with long-tail keywords... you can end a sentence with the first part of the KW and begin the next sentence with the rest of it, and the reader doesn't feel like the keyword has been "stuffed" into the content.
Just write for the visitors....the sentences should make sense to a reader to your website...search engines do find your page even for long tail keywords so if it does'nt get found for your particular keyword it will still get traffic because of long tail keywords
All punctuation is ignored. Oh, yeah. Take care of something that even doesn't have any value and everything will be ok. What kind of advice is that? How it is related with the question?