It depends on the type of content you are writing. For say, if you are covering news articles, it would be better if you mention the date in the URL: as also in the article, somewhere.

But if the articles are basically ever green content, you should be better off with dates.

_Again I do not like the approach. It seems like you are in a hurry to get as many links from different websites as quickly as possible. Do not treat link building that way. Take it as an attempt to gain exposure and believe me it is time consuming. For say, to get your website approved by Dmoz.org, you might have to wait for 6 to 8 months on an average. Moreover, instant approved directories are not that great as spammers mostly troll there. So, hold the horse. Prepare a list of niche and quality directories and then approach them. _

Blog commenting is a great way to be a part of a discussion and you should use this medium to promote yourself. Using keywords in the 'Name' field does not look natural and it might be treated as an attempt to game SERP. So, you should be better off if you use name rather than keywords in that specified field.

Ok the thing is, if text is humanly readable, you are safe. Just because you are using white texts and then something goes wrong with the style and the texts go invisible for a few days will not necessarily get your website banned. However, here I am assuming that you are not stuffing keywords there