Well, isn't it fun to have a group of solo's all with an empathy of 10?  Let's look at what an empathy score of 10 really means.
    A good example of an empathy 10 character would be Belldandy from Oh My Goddess! (aka Ah My Goddess!).  She does not let harm come to any, as long as it is within her power to do so.  A good example of this being that she has the power using the "God's CD" to lock away the demon Mara, however, if she seals Mara away, the seal cannot be broken for 500 years.  Belldandy believes this to be even too harsh for the demon.  When a character shows sympathy for his or her most hated foe, that is a good example of an empathy 10 character.  However, let us not forget that even empathy 10 characters do snap, so do not let a character who snaps at one point or another immediate move you to make their new score a 2.
    Now, getting to how all this deals with roles, your profesional career choice will have a great many effects on one's empathy.  Let's face it, if you kill people for a living, you aren't likely to feel sorry for many of them.  This is why, I recommend reflecting this by putting a roof on certain role's empathy scores.  More or less, if the role is strongly related to combat, the empathy score will not be any higher than an 8.
    On the flip side of the coin, those who do things to save lives, will likely have an empathy of average rating or higher.  This is why , when medtechs are made, I recommend a minimum empathy score of 5.  However, do not apply this to medtechs with a killing base, instead use the combat-role rule.  For example, Player A is making a medtech character, then generally he would have the minimum empathy 5 score impossed upon him; however, he declares that his character's profession is making poisons, and harmful biotoxins, then the combat-role rule of an empathy score of 8 or less would be applied.  (I personally would make it 6 or less in such a case, but that's just me.)
    Now, I understand some people might be looking at their fixers, corps, cops, rockers, and people who don't fall into the previous catagories, I recommend, for them, that they wait on what their personalities are, THEN decide what their empathy score should be.
    As always, if the player can come up with a good enough reason, and role-play the empathy score for their character, then I say, "Do it!"  These rules and comments are in no way binding.  I can see solo's who don't like killing but do it for one reason or another, I could see a Medtechie who hates people so much that he takes his appendectomy patients and replaces their limbs with cybernetics while he's got them on the table.  Anything is possible, it's a sick, sad world out there.
    A short chart below shows some sample ranges for roles and their empathies.