Sometimes raga-marga devotees are seen to worship or honor vaidhi-marga dietys. For instance Sri Caitanya Mahaprabhu is known to have sung the prayers to Lord Nrsingha Dev. So is the type of ecstatic devotion that Mahaprabhu expieriences when singing that prayer or when visiting the different Vishnu temples considered to be in the vaidhi-bhakti category?
My natural inclination would be to think it is not vaidhi-bhakti, but then on the other hand Iam not fammiliar with the idea of one being able to worship Narayana, Nrsingha, Ramachandra, etc with the disposition of a raga bhakta.
(I know I used Sri Caitanya Mahaprabhu as an example of raga a bhakta, wich of coarse He is, but I could not think of another example to fit the scenario.)
Okay, I thought of another example. In Vraja-dhama the devotees are also worshiping Lord Narayana, of coarse this is only a pastime taking place in the context of the Vraja lila, but still is that bhakti they express twords Lord Narayana considered to be in the vaidhi bhakti category?
When Vraja-bhakti (raga-bhakti) comes in contact with aisvarya (godliness) it never becomes vaidhi-bhakti. By definition it can't; the raga-bhakta's dominant emotion (daysa, sakhya, vatsalya, madhurya) is called sthayi-bhava, meaning 'permanent' (sthayi). Once this awakens in the heart it never changes. Displays of godliness on the part of Krsna only serve to augment the sthayi-bhava of his devotees. When Krsna lifted Giri Govardhana--an overt and unprecedented display of aisvarya--how did the cowherds react? It wasn't "Wow, look! Krsna must be God!" rather it was "Krsna is strong, but I've beat him in wrestling, so he needs help!" then put up their cowherding sticks to help him hold up the hill.
A raga-bhakta will see Vidhi-marga Deities like Visnu, Narasinghadeva, Rama, etc. as different aspects or 'faces' of Krsna. They will show respect for them, as Mahaprabhu did in many instances, but the devotee's raga for Krsna never changes. The example you gave of the Vrajavasis worshipping Narayana is for the sake of the lila. Vraja lila appears to be ordinary, just as Krsna appears to be an ordinary boy. In order to maintain this ordinary appearance the Vrajavasis worship God as part of their daily duties, but this takes place within the context of loving Krsna. Their love for him never changes or diminishes in any way.
With regard to Narasinghadeva in particular, Guru Maharaja has spoken many times about how we as Krsna bhaktas should consider him. Narasinghadeva is known as the destroyer of the obstacles to bhakti, so we pray to him to remove the anarthas in our hearts so that we may love Krsna. After all, he is Krsna, but in a different mood.
Thank you for the comprehensive answer.