Why wouldn't it be? The truth of the matter is your best teacher of what works and what doesn't is going to be playing it out yourself and seeing how the deck does against the wealth of horror that FNM will bestow upon you. You see a lot of flaws very quickly and you learn to correct them.
My main deck is an Abzan Morph Dragon deck, and the first time I got to play it competitively, after making changes post-rotation, was at the first day of Game Day. I got stomped and took last place. I took it home and changes were made. On the second day of Game Day, I went to the final two and took third (not quite sure how that worked, but whatever). Point is, you'll see what is working and not working in competitive play, weaknesses and strengths both get highlighted. Don't worry about the first few losses with your first deck, as they happen and nothing beats everything in Magic.
That being said, the only thoughts I'll offer are to be careful of cards that demand more than one of the same color in their CMC when playing a tri-color deck. You seem to have enough black to not worry too much about the ones in your mainboard, but those
Planar Outburst in you side may not be as helpful as one may hope. Other thought is the
Mindwrack Demon being a bit of a double-edged sword. The card's a tank in the right kind of deck but if
Delirium doesn't get triggered your opponent may just sit back and watch it kill you. Just a forewarning, but this is also just me eyeballing the build. How it will actually do, will remain to be seen. Take it out on a Friday night and then decide what can be done better, and remember that everything is always subject to draw.