I would start looking for a single solution only with magento 2, using the magento 2 extensions for blog and questions.
unless you have some crazy idea to maintain and design all this separately.
this will speedup development and you will have only one framework to follow updates.
make it simple. users dont care about your backend, and developer will ...
See table (core_config_data) in your database.
Search below paths under path column:
(web/unsecure/base_url) and set Url without https.
(web/secure/base_url) and set Url with https.
After that your website will work fine.
all you need is to create your store/website in magento, define base url.
add DNS record and point to your ip address.
in nginx or htaccess write store code assigned to your new shop view: