Short of Infiltration, Palming, Shadowing, and Tracking, physical skills aren't that much use unless you're the person that has them. Given the obvious nature of a spirit (both physical and astral), Infiltration, Palming, and Shadowing really aren't that useful, better off with the Concealment power (which plenty of spirits have).
Keeping in mind that they cannot use any AR or VR interface whatsoever, their access to DP bonuses on many technical skills (AR plans being the obvious modifier). They'd have a hard time using demolitions if the bomb relies on a digital display (Street Magic, pg. 92).
Add to it, you have to carry any / all gear that you're going to ask the Task spirit to use (hey, Spirit, pick this lock! "Of course, master. Lockpicks, please?" What, you need those!? Crap, not on me...), Just about every Technical skill requires tools, are you going to have them all on you?
To top it off, they don't have the specializations or qualities that enhance their DPs the way a real character does. This limits their DP to Force * 2, for anything tied to a mental stat, add or subtract 1-3 dice for physical, plus equipment/situational modifiers. Until you're talking Rating 5 spirit, that's not a very big DP. And even then, it's paltry compared to a competent runner.
They're handy, and useful, but not really overpowered, if you keep the above in mind.