Questions on ERC20 Tokens

I learn UNDERSTAND THE ERC-20 TOKEN SMART CONTRACT and I’ve a 3 questions.

1. What actions updates it? I solely see a price set on the level of contract creation. My guess will likely be burn and mint actions (or are there different actions?). Which ends up in the second query
2. Why is Mint and Burn not a part of the ERC20 interface?
3. The whole provide is assigned to balances[msg.sender]. Appropriate me if I’m improper, however this implies the account that deployed the contract mainly owns all of the tokens firstly? Is there not some safety fear right here? If the non-public secret’s compromised that the funds will be moved from it to another accounts! Has there been instances of exploits that occurred due to this? In actual life scenario how do folks deal with this safety dangers? Are there a special form of ERC20 the place provide is unfold and held by a number of accounts?