How you build your blaster largely depends on where you want to be in the fight. It looks like you're going for standing in the middle and relying on Hot Feet. Not my choice, but it can work if you remember to pop purples. From my experience, hovering out of melee significantly improves your survival, which negates using Hot Feet and Fire Sword Circle. Lately I've been more focused on trying to improve my ST damage and stay out of melee as much as possible, but still have enough defense/resistance to survive whatever is left after my alpha. Of course, if you aren't dying as a blaster you're not doing enough damage, which is why ROTF is handy.
This is what I'm using at the moment. It's not the greatest, most optimized build but it works well for my playstyle. My goal on a team is to do hellish amounts of damage as quickly as possible. Aim slotted with Gaussian's Build Up proc is game-changing for damage output.
For groups my attack chain looks like this: Aim, Rain of Fire, Fire Ball, Fire Breath. If someone is grouping mobs I'll drop Aim/Build Up and Inferno. If anything is left standing it's Blazing Bolt, Blaze, Fire Blast/Fire Sword. If I get in trouble or we need some extra control, Bonfire slotted with KB to KD is amazing.
Good luck! I've played a lot of characters to 50 but blasting is by far my favorite.
Blaster (Fire Blast).mxd
