Regarding your question about the picture of Lord Caitanya with six arms: This form was shown to Ramananda Roy, and Sarvabhauma Bhattacarya. This is called Sadbhuja Murti. This Sadbhuja Murti is worshiped also by the devotees of Lord Caitanya, and especially the Murti is situated in the temple of Jagannatha Puri. Sometimes when you may go to India and visit the temple of Jagannatha, you will find this Murti.
Affection for God-brothers is nice, it is a good sign. Affection for God-brothers as well as for all other living entities, even they are not God-brothers, these signs are seen in the advanced devotees. There are three kinds of devotees: The lower grade devotees, they have high regard for the Deity in the temple, but not very much regard for devotees or people in general. The second grade devotee takes compassion with innocent non-devotees. In that stage, he has got 4 kinds of vision: one is that he always keeps Krishna as the most Lovable Object, second is that he makes intimate friendship with his devotee God-brothers or any other devotees, third is that he takes compassion with innocent non-devotees, and tries to convince them about the importance of Krishna Consciousness, and fourth is that he does not take any serious interest for the atheist class of men. The first grade devotee, of course, sees everyone in relationship with Krishna and as such, he makes no distinction between a devotee or nondevotee. His vision is high grade, because he sees that everyone is engaged in Krishna's service directly or indirectly. This position of high-grade devotee should never be imitated. It was possible only in Lord Caitanya or Lord Nityananda, or Haridasa Thakura. Thakura Haridasa was so powerful that he could convert even a harlot. But we should not try to imitate Haridasa Thakura or Lord Caitanya. Our position is in the second grade platform. We should not be satisfied remaining in the third grade platform. But we should try to elevate ourselves in the second grade platform. So far the first grade platform is concerned, it is not attained by our endeavor, but it is possible when we have full Grace of Krishna. It completely depends on the causeless Mercy of Krishna.