If you must solo level that's what I would do as a shifter.
Evil or good human, probably good, advantage being you an get some better gear solo since you have the request feature, though you should loot at that as a bonus instead of a reason for alignment.
I would take defense/water or defense/offense. or if yer really crazy water/defense.
Lvl up to first form as much as you can on mobs, only doing quests that expire at a certain level, save the quests that you can do at any level for when you really need them.
when you safely can, read everything in the lyceum, look at everything in any areas you can safely go to, HTOS, and any other areas, look at every single mob in the area, turn in the explore/obs exp. You should be able to squeeze at least one level out that way and as a bonus you might learn of something you didnt know of yet.
Once you get a form it will stilll be slow going, but you should be able to fight perfect match mobs somewhere for some slow exp, keep in mind not all perfect match mobs are the same, try to find some
that have an attack type you resist, or dont have spec skills, or do low damage or such, ensure that they dont bash/trip you, when you're solo leveling every mob death counts.
Obviously you know to be wary of pk and that people will be looking for you, but remember this, teleport is not your friend if you're doing painfully slow leveling, A PK death doesnt cost you xp, a teleport into High Lord's keep will. So if you've run out of escape options and only teleport is there, fight the good fight because 15 minutes of ghost time and 1/3 con is better than 1-2 hours getting that level you were just about to get back. While leveling as a shifter that you are concentrating on leveling instead of pk I would concentrate 100% on hp gear, you will be hurt and have to rest before you run out of mana anyways. If you are planning on leveling all the way solo, A water form can be a huge boon that's why my water suggestion is in there, otherwise the defense/offense combo give you the most usefull solo leveling greater enlivens and the highest chance of regen forms so you can rope a dope mobs if you have to.

The other thing to remember is solo leveling anything isnt easy, doing it on a shifter even less so, have patience and play conservative so you dont end up in an exp hole, setbacks will be very painfull.