Is it permissible for a Muslim to say "I wish everyone was like you, O Lord" intending the diligence of a disbeliever in their work, and to say "May Allah reward you with good" to him, intending to invite him to Islam?

There is no harm in praising a disbeliever for their diligence in work, provided that the praise is qualified so as not to imply commendation of their false religion. Similarly, there is no harm in saying "May Allah reward you with good" (Jazakallahu Khairan) to a disbeliever with the intention of guiding them and improving their condition, due to the general nature of the Islamic legal texts in this regard. It is, however, recommended to be keen on inviting them to Islam and clarifying the falsehoods of their religion.