FM/ELA/Blaze question...

Okay, I have a new purely concept choosen powers (but I'll use IOs to the best of their abilities for the character) that I just don't see her using a bunch of fire swords.

As of now her ST chain looks to be...Incinerate - Scorch - Cremate - Scorch - Repeat.

Roughly 170 DPS with just that chain, enough for me to live with at any rate.

The concept was basically me wanting to make a Supergirl/Power Girl/Superman style hero...you know...bullets bouncing off of her type...but I prefere Scrappers over Brutes and Tankers, and the only thing that I really wish I could have in my concept is Hurl (lousy attack it may be, but I love it )

So, instead of MA/INV...I got to thinking what other combos could I use, then I thought of Firestar and my FM/ELA was made. Good Resists, a self heal clickie power to use and basically what's been a fun scrapper so far was made!

But I'm tryong to figure out if I should put Fire Blast into the chain. MiDS is really wrong on the damage for the Fire Epic it seems, so is Fire Blast equal, better or worse DPS than Scorch?

Next, there is little I can do to increase the resists (though I'd love to get the S/L up even more, to the point I'm seriously considering working towards getting the +3% Resist IO), so my question is...

How much defense do I need to build for to make the self heal and resists be enough to stand up to AVs without inspiration use?

Also don't want to take any Incarnate slots into account except for the Alpha (I was thinking Cardiac for the increased Resists) and Interface (basically the passive incarnate abilities).