If you are concerned about handling 100 mg/ml nic base, cut the concentration in half by diluting it. For example, carefully measure out 10 mls of 100 mg/ml nic solution and dilute it down with either 10 mls of PG or VG. You'll now have 20 mls of a 50 mg/ml nic base. Using equal volumes of nic base and dilution liquid is easiest to calculate, but you could ratio it any way that you prefer.
+1 I practice what you preach. I buy 100 mg and store it in the freezer full strength, it takes up less room that way. I keep my "working bottle" diluted to 50 mg by measuring 25 ml of nic and 25 ml of vg in a graduated cylinder, then pouring into my working bottle. As little as I mix I run through that 50 mls in about a month, so it doesn't have time to get old and change colors/taste.
I would say don't be "afraid" of 100 mg but definitely "respect" it and know what's safe when it comes to handling. Good luck!