Compatibility and Up to date?

It has not been updated in 2 years, I don’t think its safe unless you want to work on it.

See https://wp-themes.com/thematic/ – latest version of wordpress

Hello Andrew,
when following your link I just see a demo.
I’m a newbie in WP, but oldtimer in blogger.
Would it be safe to use thematic?

Probably in most will work, but I think devs moved to undescore theme