I'm a fire/dev blaster myself so I think you're going to have fun, a few points to make however.
If you're going to insist on flares, it only needs 5 slots, 3 damage, 1 accurace and 1 range increase. All your other main attacks (like fire blast, blaze, snipe) should be 6 slotted with 3 damage, 1 accuracy and either 2 end. red., 2 recharge or one of either, depending on it's cost. (For example, fire blast is better with 2 end. red. because it's endurance cost is high but recharges pretty quicly on its own anyway.)
Personally, I avoided Rain of Fire and Fire Breath as they really aren't that good - they spread mobs, don't do that much damage and aren't really main attacks. I also avoided Caltrops because although they do slow enemies down and help in PvP to prevent AS, they also scatter mobs, cost a lot, have long recharge even with SO's and aren't that useful in PvE.
Time Bomb is an interesting choice. I didn't take it because it has a 15second period before it blows, in that time you've either killed your enemy or it's moved, but go for it if you like.
Also, in my first build I took Swift, Health and Stamina in that power pool, but I really didn't find that much of a difference with Health. I have SJ and acrobatics which gives me some resistance to holds, and so decided to opt for Hurdle instead. Obviously you have fly not SJ, but just thought this might be something to consider.
As for your epic, I debated for a long time whether to take the fire epic or munitions, and eventually opted for Munitions. It provides you with a good hold (waaaay better than web granade) an armour (essential as a blaster) and a really good missile for your last power (as far as I can remember.)
It's up to you how you play you're blaster - good luck! Hope this was helpful
Thanks again.
