The setTokenAddress() function doesn't validate that _saleToken is not the zero address. If a zero address is set, the contract will break when trying to call IERC20Metadata(saleToken). decimals () on line 735, and all token operations will fail. Add a zero address validation.

The function doesn't validate the referral rates in the _levelRate array. The owner could accidentally or maliciously set rates that exceed 100% (10000 basis points), causing the referral system to distribute more tokens than intended. This could drain the contract's token balance or cause accounting errors. Add validation for reasonable limits. Without validation, referral rates could be set to values that break the tokenomics and potentially drain the contract, making it a real financial risk.

The setVestingInfo function lacks parameter validation, allowing owner to set vesting percentages exceeding 100% or zero cycle times. This could enable users to claim more tokens than purchased or cause division-by-zero errors in vesting calculations, potentially breaking the token distribution mechanism.

The setMinimumBuy function lacks upper bound validation, allowing owner to set extremely high minimum purchase amounts that could effectively lock out all users from participating in the presale, making it inaccessible to regular investors and potentially restricting access to only whale participants. Add maximum threshold validation: require(minbuy <= reasonable_limit) to prevent setting unreasonably high minimum purchase amounts.

The contract uses SafeMath library with Solidity 0.8.25 which has built-in overflow/underflow protection. SafeMath adds unnecessary gas costs and code complexity since Solidity 0.8.0+ automatically reverts on arithmetic overflows/underflows, making the SafeMath library redundant and inefficient. Remove using SafeMath for uint256; and replace SafeMath function calls with native arithmetic operators.