DIY e liquid seems daunting at first and you may worry about quantities etc, getting them spot on the fraction of a drop. But after you have found a mix you are happy with, it becomes easy as making a cup of coffee. Its just a learning curve, and once you have learnt the ratio of pg:vg:flavouring that you like, then it is quick and easy.
With regards safety, even the 54mg nicotine base that you can buy, is well diluted with a diluent such as PG or VG. If it gets on the skin, you simply wash it off. Because it is dluted so much in PG, it does not absorb well in the skin anyway, not like pure nicotine.
There are 1000mg in a ml, and each ml of 54mg base, has just 54mg per 1000 of nicotine. So it is pretty well diluted at those levels. Although obvious precautions have to be taken, nowhere near kids, dont drink it, dont bathe in it, dont vape it neat etc. However as long as you are sensible, it is really not as scary as it may at first seem. If you get it on your hands, just wash it off.
The main benefit is that it saves alot of money, plus you are in control of flavour concentration, strength etc.