CentOS i believe require higher hardware specification compare to ubuntu derivatives like Mint. For all the lists of things you wanted to o, Puppy linux can work well and it can be installed to an old computer.

I'm already aware about renting my profile signature to advertise a product under my posts. But I'm sure my profile isn't something useful to market any product as I'm a newbie. Can you guys lay me some options as to what to do or where to start to earn bitcoin?

Basically you can do anything using the derivatives of ubuntu. if you can work with puppy linux which is small and fast that would be great. which software do you use for creating subtitles by the way?

as far as i know you can encrypt text using the openshot software and inkscape