non WordPress blog that I can own

[Larry01]

I am not a fan or WordPress but it is the safest place to create a blog which I can own and sell in future if I wish.

Prefer blogger.com or timblr but these can be taken away "just 'cause".

Is there any control/ownership protection if I create a blog in Nabble?

[GregChapman]

Not sure what you mean by protection.

Nabble provides a service over which you have no control should they decide to stop running the service - the same as all the other service providers you mention.

If you want control then why not rent server space, install WordPress or any of a score of alternative blogging software platforms, then you can back up everything locally to protect your product should your current host go down.