Hi @zotezo,
Thanks for contacting us, I will try to answer you in our respective scope, the AMP for WordPress Plugin, concerns about Google Search and the AMP project please check the respective channels. But I will try to answer all questions.
1) Will AMP Obsolete after 1/2 months?
The simple answer is No. AMP is constantly evolving, now the project is part of the OpenJS working group, where every year the ecosystem is growing for itself, branching to different projects. Now we have Web Stories, Bento that are nearly launched that will completely change the ecosystem. And some of those changes are related to developers and users and users feedback.
That is why Bento was born at the same place. To give the power of AMP components without being restricted to AMP pages. In parallel, AMP for WordPress is a project present in more than 500.000 WordPress websites, uses the power of AMP to deliver a mobile first and fast experience. In other words, the plugin improves the front-end performance from your website, with components following the best coding standards, Markup improvement and CSS compression. A lot of work is done to give users the power to keep improving their website performance and user experience.
2) AMP will not be Ranking factor in Google Search console, is it true?
AMP was never a ranking factor, but for example, speed is a ranking factor, and AMP helps WordPress users to archive this ranking factor and others, with the tools provided by the Plugin and the AMP cache for AMP valid pages. Just a reminder talking about WordPress ecosystem are a one variety of items that can influence a WordPress performance, such as, Hosting, cache tools, and quality of access and a well-balanced structure of plugins.
3) In Pagespeed the rank that is showing individual page wise,is it the rank of the overall site not the specific page?
Pagespeed insights shows reports from pages individually, the best place to have an overall report is on Search Console.
4) How can I exclude several custom post from AMP?
If you want to remove AMP from a specific post, you can disable AMP, using the editing post sidebar:
Or disable AMP for a specif post type:
If you have any other query, please let me know