It states in the starting skills specifically on its own:" and are Trained in Tech-use". Does this mean that characters from this home world will have tech-use +10 in the beginning?

No, it means the trained box is marked for the skill. Meaning that it is a base +0.

The skill levels in the book are known, trained, experienced, veteran. In the only war character sheet have been written wrongly. Only war book 102 page states Known as can use skill without -20 penalty for untrained skills, Trained receives +10 on all skill tests, and the rest +20 and +30, so there is a clear controversy.