Global, Site:

SEO settings:

SEF URLS: yes

Use URL Rewriting: from no to yes

Cookie Settings:

Cookie domain: .domain.com

Cookie Path: /

Global, System:

 Session Settings:

Session Handler from Database to PHP

Session Lifetime: from 15 to 30

Global, Server: 

Force https: entire site

Server Time Zone

Mail settings: from mail and from name, PHP mail

Global, Articles, Integration:

URL Routing: from Legacy to Modern

Remove ID's from URL: from no to yes

Enable Custom Fields: from no to yes

Global, Contacts, Integration:

URL Routing: from Legacy to Modern

Remove ID's from URL: from no to yes

Enable Custom Fields: from no to yes

Global, Templates:

Preview Module positions: from disabled to enabled (?tp=1)

Global, Users, Integration:

URL Routing: from Legacy to Modern

Enable Custom Fields: from no to yes

Modules:

Login:

 show name/usersname: set from User to Username

Plugins:

System - SEF:

 set email domain name (https://)

System - Session Data Purge:

 Probabiltiy from 1 to 10