Is is safe to rewire a phone jack with your fingers?

I qualify this carefully as I'm sure there are some who will cringe at this answer. But I have wired one heck of a lot of phone jacks with my bare hands. That doesn't mean it's right... it just means its more of a common practice. There isn't enough current on a phone line to ever hurt you.

You usually won't feel the 48 volts DC, but if someone calls in, it goes to about 90 Volts AC, It will just Make you Jump. Never have know it to hurt or kill any one.
If you are working with one conductor at a time, and you are not at ground potential, you won't get shocked.

I was a US Navy electrician. We were required to work everything with the assumption it was hot and could cause injury (including communication circuits). There are studies that say very minimal amperage under the right conditions can kill you espec. If they pass through the heart. Most electricians don't want shocks of any kind at any time. Would you have confidence in an electrician who jumped and dropped his tools every once in a while?
Our policy was to work it like its hot (insulated tools) except for new circuits that you know are not hot because you are the one who is going to make it hot. I am not a licensed electrician.

Don't know of any electricians that haven't been shocked. Electricity is silent and invisible.
It keeps you on your toes.
I agree to treat everything like it is hot. And stay insulated.
And if you are wiring to a panel. Make connections furthest away from panel, and work torwards Panel or live connection. Then you only need to work with live connections once.
The High Voltage Guys have a saying, "Work it Live, or Ground it Cold"
I have a Leatherman Tool(Keep with me all the time). And when you need to change a receptacle, you remove the ground wire first, then the hot and neutral.
When you hook up the new receptacle, you need to hook up the hot and Neutral First, than the ground, to keep from getting shocked, from being at ground potential. Insulated shoes are the trick. Don't do that barefooted. You should not do any of it. I have done it so many times it is habbit.