Found this article
https://www.electricbike.com/52v-battery-3077-fet/ talking about voltage limits.
BTW, the OP should find the article very interesting. It hits all the topics he mentions.
Anyway here is what this guy said
According to ISO 60950-1 (electric shock, 0.2.1, page 23), it is safe to touch 60V DC in a SELV circuit, and this standard is used in both USA and Europe.
If we think about this for a while, we can construct a situation where someone can be killed by only 36V. But…lets just say for the sake of this argument that…100V DC will absolutely penetrate human skin…just by touching it (24 cells in series, 24S, in case you were curious). The 58V of a fully charged 14S battery will not penetrate dry human skin under normal circumstances, and if the skin is damaged from high amps, the amount of internal tissue damage will be the result of how long contact is maintained (meaning tissue damage will occur at even 36V if the skin is opened by high amps)
The farther you stay below 60V, the safer you will be. However, the international standards for voltage penetrating the skin are…voltages above 60V.