1 is s the other is m.  If have S or M someone is masturbating and having a fantasy.

but we are stuck with the nomenclature for better or worse.

Some gals (I'd say the majority.) are doms, meaning they dish it out.  Subs like to be on the receiving end, and then some will do both.  The actual practices can vary also from light spanking to using whips, and then there are all the fetishes involving humiliation, role playing, etc.  It's quite a big world with a lot of interesting flavors and dimensions.

The best way to figure out what you are likely to get is to read the reviews, and of course look over her website.

You probably should not mention specific providers in a post like this.

It it just saying in some manner, S&M is available, just as rimming is available, but unless you outright ask, you don't know which way they go.

Also, "More than one guy at a time" could use some explanation as well. I have "no" on my profile, because I am under the assumption it connotes DP, which there is no way in hell I would ever do, but I have no problem sucking one, whilst getting plugged by the other lol.

Yes, it should, but S&M, just like BDSM, is usually just used to refer to the practice in general.  I wouldn't pay a lot of attention to that field on the TER profile unless it says heavy.  A little bit of light spanking is fairly vanilla.  But, most women who go for BDSM prefer sub/recipient role.  (Yes, it has been studied.)  

If you are looking for some mild sub, you may be able to work it out with quite a few providers (it might take a second date), and it really depends on what you mean by mild sub.  If you want real D/s, then you will have to work a little harder.  Look for the heavy in the TER field, and check the reviews and their websites for specifics to see if they are D or s.  And a real D/s relationship can take some time to establish or you won't get the true submission you may be looking for.  

And just to be clear, D/s doesn't always include S or M.  I have a play toy who is not into pain at all.  Just submission.  This is all probably a lot more than you wanted to know, though.