I would revel in contemplating abstract philosophical questions about being and soul. I'd try to find harmony through such phenomenal abstractions rather than objectively predicting 'natural harmony' because logic coldly plays itself out. Hence, truly experiencing the feeling of harmony.
I'd devour the feeling of a soulmate over a mindmate.
Well, I'm already rather familiar with Fe, so I guess I'd be tempted to continue that way. Of course, my Fe is a bit like the inner child that still lives within me, and I guess that experiencing a mature, responsible Fe (like the one of natural users) should be quite a change.
In fact, I guess I would have more trouble caused by the Ni, and the odd concepts gathered around this mysterious function.
Since I'm already a rather happy/optimistic ENTP, most of my emotions already are centered about happiness and Joy, I guess. So, more or less emotions... why not... as long as it's a thrilling experience.
Emotions are also very useful to give inspiration.
"A man who only drinks water has a secret to hide from his fellow-men" -Baudelaire
If I was an NF for a day I'd spend that day thinking of how I could make me the very best NF. Also I would reflect on how I could help people with my new found NFness.
I'd immediately join an NF related forum and share in the inner joy that it is to be an NF. Not only joy and merriment for me though I would also share my deep concern for people and their personal growth as NF with others in the NF forum.
I'd also install the emoticon add on in firefox.