All the maximum values for those fields depend on the jurisdictional chip.
Bill and Coin- Limit - This is the amount at which time the validator will no longer accept currency and the coin-in mech will reject all coins. If the bill you are inserting will take the credits over the credit limit, the bill will be rejected.
AFT/Voucher Limit - Same as above, but it applies to electronic transfers into the machine as well as ticket vouchers.
Credit Limit - If any action takes the machine over the credit limit, like you win a huge jackpot and takes you over this limit, the system will either handpay the win or pay out with ticket.
Upper Jackpot - If a jackpot is over this amount, it will either be handpay or paid out of tickets.
Jackpot Limit - Any win over this amount will go into handpay. ALL US jurisdictional chips have this maxed at $1,200 due to income tax reasons. This basically makes any jackpot $1,200 and over go into handpay mode, and will not be added to credits no matter what your other limits are set to. The only way around this is to get an international jurisdictional chip, then you can set this to a really high amount.