have you already looked atAssets Migration Guide

You should enable debug logs com.day.cq.mailer.impland observe the logs when DefaultMailService is getting activated.It should print the configuration debug message in activation method"MailService activated, fromAddress"Or check logs for messages like"Invalid mail service configuration""No mail service configuration present."also check the component com.day.cq.mailer.DefaultMailService in components web console (/system/console/components), see if you see the configuration properties for

Please check User ("The Adobe AEM Quickstart and Web Application.")

a file is created in dispatcher cache because dispatcher is trying to cache the file, when you try to publish it or go to details page. Browser must be sending a get request for the file and dispatcher must be caching it.In case of folder, there is no such file requested. dispatcher will not cache any thing.Why do you want to rely on folder or file being created in dispatcher cache

if you create right replication agent, then the replication between publish-publish should also work, please see similar thread AEM 6.1 | Can we configure replication from publish to publish ?

which sharepoint connector version are you using. Connector no longer support mount points with OAK repositorySharePoint Connector

There is a new version of Sharepoint Connector available with 6.1, please read the documentation to understand what it supports and what it does not. There has been some changes, most importantly, there is no live mount support now with oakhttps://docs.adobe.com/content/docs/en/aem/6-1/administer/integration/current.html