Does an over voltage, over current and reverse polarity protection IC exist?
If you want your circuit to be tolerant of over-voltage, you will have to specify up to which voltage, because your protection circuit must be built to withstand that voltage.

If you can afford the drop a diode bridge is a sure way to be polarity independent. You can eliminate the drop by using a relay.

For over-current you will have to decide what to do when you detect over-current. Limit the current to the maximum value? That implies a linear element, and hence (lots of) power dissipation! Another option is to cut of the power to your gadget until power is removed. This implies some memory element, a thyristor can be convenient for this purpose.

Note that your wish not to have a fuse makes a huge difference in cost: otherwise a fuse + power zener diode would do the reverse and over voltage protection, and a current triggered thyristor crowbar would do over-current.

You seemed to be unhappy with the drop for a series diode. You must realize that almost any form of current monitoring will need some voltage drop, and lower drops require a more complex circuit..