Thank you for all your inputs. We have decided to explore the information received from external systems to be stored in browser session. Lets see how it goes. 

Interesting !! I was looking for answers to the same question. 

Hi Jorg - are there any strong reasons for this recommendation. Little more direction would be helpful. Thank you

My only worry points are storing 50000 users info and querying them time to time when the user logs in for personalization purpose. Is AEM JCR meant for storing such data or is it recommended to have the external DB to store that info. .

Thank you for the suggestion. I will try adding GTM script first and monitor it closely if any performance hit.

We have been told to upgrade from 6.2 to 6.4 almost 8 months back. It was insisted to upgradeYou might have heard AEM 6.5 is announced and few details given below.Announcing Adobe Experience Manager 6.5

Do we need cq:conf property or is it optional. I dont see that on my root page and I am able to create page with my new template.

Check if you have multiple java versions and also make sure java -version is pointing to right version. Delete the quickstart folder and try installing once again. If not last option try, using the command line to start.

Are there any issues with google recapcha that you are looking for alternatives.

I am having same usecase. I am wondering if there is a relation or mapping provided in between designpath and clientlibs. Previously I used design in order to apply the styles to a website. Clientlibs is being the preferred approach which is we can apply the appropriate style in code using data-sly-...