euro-spacenet

You can try this:

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

Hi, first of all, you should never use http when connecting to ftp, but ftp://ftp.addondomian.com or ftp://addondomian.com. Best of all is to install FTP client like FileZilla, write maindomian.com / addondomian.com in Host, ftp user/pass and connect.
Another solution is web based File Manager, which comes with most web hosting control panels.
If you’re using cPanel as a control panel and need to transfer full WP sites with their databases etc. you can easily create full-site backup in cPanel and ask your hosting provider to migrate to the new server/domain.

If there’s phpMyAdmin, try to import with that tool.
There’s alternative way using single-file MySQL management tool by adminer.org , which could be useful.

If you have access to .htaccess file writing following must be enough for the redirection:

Options +FollowSymLinks
RewriteEngine on
RewriteRule (.*) https://www.newdomain.com/$1 [R=301,L]

Please replace https://www.newdomain.com in the above code with your actual domain name.

Sometimes slow loading speed could be hosting problem, especially if your webhosting provider has many accounts on the single server causing overload or many simultaneous connections to the MySQL database.

You won’t need to change anything if moving from one cpanel to another cpanel hosting, just make a full-site backup from cPanel and restore that backup on the new server (you might need to ask new hosting provider to do that for you if you don’t have a root access).

WordPress is available with almost all paid hosting providers.
If you look to the WHOIS info of the domain, you can easily find the hosting provider by the nameservers.

Why spend money with the vps, on it’s management, panels, etc. which will take big part of your time and efforts?
Better get some good shared cPanel hosting with preinstalled WordPress if you run small / medium size website.
For a high traffic and loaded sites, sure, it’s better to have a VPS plan.

For the future reference, if you want DB / site backup, use the xCloner plugin, which is very helpful with site moves.
Changing nameservers with the domain, sometimes could take about 24 hrs.

Well, you can do that with WordPress, maybe might need to do some modifications as well..