Do you have to be pagan to use runes? Do you have to be Norse? Do you have to follow Norse gods (Odin, Thor) to use runes? 

Answer to all of those questions is – no, you don’t have to follow any particular tradition, beliefs or gods to use runes and rune magick.

The 24 runes represent the universal archetypes/energies. These energies and archetypes are present in any tradition, language, country, religion. 

The Elder Futhark runes are even older than the Viking age, so it is not correct to call Elder Futhark as “viking runes”.

Runes are universal and anyone can use runes. 

Can I work with runes if I am Christian, Muslim, Atheist?

There is nothing preventing you from doing any kind of magick other than your own fear.

It is for you to decide and to bear the full responsibility of your decision. If you are still not sure, you can just work with runes considering them as universal symbols, and skip everything related to Norse gods.

Or, you can adapt the rituals for your religion/god and make runes as part of your religious practice.

As far as I know white magick exists as part of many popular religions. You can use runes for white magick.

What if I don’t have any inborn magical abilities?

If you exist, you have magical abilities. In modern times all people have some magical power in them. 

Only in very rare cases, there can be actual blocks on magical abilities. My course offers methods to remove these blocks. Also, exercises to develop these abilities.