Where is it better for me to pray: in the large mosque as a congregant, despite not feeling devotion, or in the small mosque, sometimes as an imam, with a sense of comfort, even if the rows are not straight?

If you are to lead the prayers in the mosque with the smaller congregation, it is better for you to go there to attain the reward of leading the prayer, for the Imam receives more reward than the one being led in prayer. Through this, the benefit of the congregation is realized for him and for others, and also because leadership in prayer brings about the congregation for him and for others. In addition, it is better to pray in the mosque where you feel greater comfort and humility, even if it is far away, for humility is superior to the virtue of the place. As for straightening the rows, it is a Sunnah according to the majority of scholars, and there is no sin in neglecting it, nor does it affect the reward of your prayer. However, it is advisable to remind the worshippers of its importance.