I
don't get your points at this because www is in url while 70 characters are for the tittle that showing on Google search reulsts, it doesn't relate to www or non www in this case.
URLs length have certain limitations from user experince point of view, shorter the url more click through rates. There is something called SERP snippet, where the pixels and character count matters. Suggest you to read this for more information.
https://moz.com/community/q/maximum-length-of-the-url-for-seo-75-115
and this
https://moz.com/learn/seo/url will clear your queries fully.
You mean shorter ones are better for URL structure?
Yes
I never heard of using date and month format that benefit for new sites? what are benefits?
Its for news website, where the current affairs are day by day information, So google will know that its a news site and do the indexing properly. This format not applicable for normal websites. News websites content is not ever green content, it is different.
It is read and discard, so in such websites using data/month/year format will be good so that two news lines or topics cannot collide and it also helps in archiving pervious news items. News websites in the sense Magazines or online news papers.
Example see this website url structure:
http://www.huffingtonpost.in/2017/0...ro-system-kills-at-least-11-peopl_a_22024772/
This is a news website.
Content is of three types:
1) User Generated content (facebook and likes, adds no value to search users)
2) Evergreen content (for example, how to hard boil egg, it is same process everytime)
3) Dynamic or Current content (example news papers, where during elections there may be some kind of rumours or false news which loose its value, once the event is over, likewise day to day things like climate or weather which is not the same everyday, so it adds no value for user. Such content should use date, month and year format for better indexing in Google).
You can learn about it here:
https://www.bruceclay.com/in/seo/silo.htm
Silo is old school SEO. It defers the new seo practices like url short length and other stuctures we discussed above. Silo is not working now, as far as i know, once customer asked me to implement for him, but it did not bring any results.
Hope this helps you. Thank you.
If you wish to learn about white hat seo, go to moz, quicksprout and kissmetrics, those are good place to start learning.