Google's mantra is to focus on the readability without throwing in extra keywords into content. I don't know how the system would ever know the keywords are getting over the top without a person actually reading it but it really seems like it knows somehow because I have some content that outperforms more keyword-rich stuff. Go Badgers.
I don't think you should insert all 50 keywords in only one page. Spread them out throughout your whole website in man web pages. Besides I don't see why you would include 50 different keywords, I think you should concentrate on your 5 - 10 main ones and work hard on getting them high ranked. Trying to get high ranked for 50 keywords is not an easy task. And to answer your question, yes it might hurt your rankings because if you include to many keywords and if most of the keywords or key phrases are similar to one another, then the search engine will probably think that you are stuffing your keywords in you content and might flag you for a review.
To many keywords can be bad, in my SEO class at college they said to select 10 keywords, and to expand your list of keywords as your site grows with more content, and gets ranked in google and other search engines.
too much keywords in one page itself in against Google's and SEO policy, it can be considered as spamming, what you can do is use around 15 to 20 keywords in homepage and extract bench mark keywords for every page on your websites, keywords used in meta tags must match with you content in website.....
There is no specific limitation set for the use of keywords, it varies in every situation. A big site can have more keyword targets than a small site.
50 keywords??? is not allowed to use to many keyword for the site.. Basically there is a magic number. Base on my own experience 8 to 10 is good to start..
Just make it look natural so it can be easily read by your visitors. Also, if you insert a lot of different keywords, your site will be seen as more of a general topic rather than specific, and it won't be ranking for that specific term as much.
No for sure. It is upto you, how much keyword you target. But keywords should be relevant to your content, otherwise it doesn't work. BTW, if you are talking about keywords in META TAG, then it doesn't work now a days. All works with your content, H1, H2m Title and URL structure only.
How long's your page? I see no reason to exclude 50 keywords from a ridiculously long page. But I'm guessing that's not your situation. Go with as many as you can without damaging the readability of the page. Google will punish you if your page doesn't appear to have been constructed primarily for human use.
If you insert too many key words on a page Google will treat it as SPAM and yes it will hurt your site.