Well, considering the many zones in the mud, it is possible for a T4 low remort thief to remort entirely without getting encircle, just by exploring (and killing mobs along the way). However, yes, it is pretty boring.
Thieves do get more skills than encircle, but Virisin is right, encircle is the ONLY aggressive skill / useful currently.
Strangle - (subskills which help are currently locked in Fenizia, so strangle doesn't help that much). Even then, strangle only works on T0 mobs. T1, T2, T3, and T4 mobs ignore the effects and attack.
Flank - Skill not done
Poison Weapon (Most poison objects are locked in Fenizia, and most mobs which are a toughie are sadly !POISON)
Trap Aware - Bugged again, thieves can't flee and attack from the shadows, rather, they have to duke it out like a warrior style
Slip - Only useful in PK, mobs which hit hard surprisingly have very little inventory room to slip objects into, and as snare is a T1 skill, slip can easily backfire without trap aware.
If encircle were to get weakened, I'd say it should be done only after the above 4 skills are looked into, else thief would become worse than ranger