I need a little help, suggestions...

Short of trying all the strings out there, as you mentioned, whitewater seems to have the perfect answer.  I like to push Kurt Mangan strings because they are very bright sounding and they also last a long time.  Give them a try.

Well, I was thinking of trying the Martin FX, but reviews indicate I won't like the weak sound.  I'm having Jim pick me up a set of SP Custom Lights and I'll see what I think of them.  Withewater's idea will work though if I can't find a string I like before Feb!    I thought about those D'Addario Silk and Steels too.  If I don't like the SP I think that might be the next thing I try!

Easy Bluesy sounding songs?  Anyone?

Well... I guess from reviews, the 000-15M is not suggested for 12's - this must be why.  Jim's at the store now.  No custom lights available.  So I told him to see if they have the FX or the D'Addario Silk and Steel in the 12's or 11.  He grabbed Martin Silk N Steel.  We shall see!  I'll let ya'll know what I think.  My Elixirs on there now are only a week or so old, so it'll be a good comparison.  LOL!

Toots, I'm scared to mess with the standard set up on my Martin for fear of having to replace anything.  The string height is just right, but up close to the nut has never played right for me.  If trying different strings doesn't fix the issues, I may just take to to where I bought it and see if they can lower the nut a bit for me.  That was the first thing they said they could do when I bought it, but they suggested against it.  Said I'd get better, then be upset.  LOL!  I guess I didn't get better!  ha ha!

Amy did you ever have your martin set up when you got it ? the action on the strings may need too be loward, you may want too pull the bridge up and see if they have any material under it and if so remove it and try it out. There are many videos on you tube showing you how too do it yourself. It's easy!! I know you could do the blues and play better if you learned the panotonic scales they are easy too learn in the blues area around frets 12 through 17 ,you can do alot and learn the next one down the neck also. you should not have too keep a capo on your martin all the time.Look around youtube they have alot of people showing you how .Once you learn them you will be able too jump into almost any song.

You can play blues a lot of different ways and never barre a note.

E A B7
C F G
G D A
A D E

That's about ten zillion songs, conservatively. 

Amy,
You might want to try some Martin Lifespan SP strings. I have been using them on my Martin and I like them. They will sound different than Elixirs. I have had good luck with the life of them and prefer them over Elixirs. I use Elixirs on some of my other guitars but I think they mute some of the sound on the Martin. I use Lights .012-.054 . They are gonna sound a little brighter to start with but settle in very nice......

Thanks guys for all your suggestions!  So far, the Marquis Silk and Steel 11's are on there and it's SOOOO MUCH EASIER TO PLAY!  Jim also grabbed me a pair of SP 12's.  I don't really notice much difference in the sound from the Elixirs to the Marquis, other than being a hair muted, but NOT BAD!  Jim hated the Elixirs and thinks it sounds better.  Could be just his opinion of the brand, or being the one standing in front of it maybe there is a difference to him.  The good thing though, I don't think I'll need to take the guitar in anywhere now!  I still think the nut could stand to be lowered a hair, but it's not so terrible that I can't play it anymore.  I can't believe those nanowebs are so stiff!

Thanks Dino for the song suggestions!  I actually have been working on The Rose now that I can play where I need to for the right sound!    Jim's already planning to maybe join us at some point via Skype during ChordieStock... I hope you will too!