Thinking of getting rid of the plug and just wire this direct. Will this be OK?

Yes, IF you have a disconnect or switchable circuit breaker.

SO if I go straight from the batteries to the trolling motor the switches on the battery terminals wont get it done?

you can wire it without the plug up on the bow, but you do need to have a way to disconnect the trolling motors power when charging the batteries.

^^^this

With or without the plug you need to use a breaker like Wayne posted. You probably already have one mounted somewhere near your batteries. Just make sure that you have the correct size. The reason for the disconnect as Wayne posted and Steez stated is because these new trolling motors can be damaged if left connected while charging the batteries. Both the parts are usually placed in the back near the battery.

It will work going direct to the battery but you are rolling the dice on ruining an expensive trolling motor.

Thanks Guys!

Am I OK by just shutting the power to the trolling motor off at the foot control switch on the Ultrex?

Install a switchable circuit breaker at the batteries and you should always turn it off when not in use.

No, the control board is still drawing power with the switch off. The switch just controls the power going out of the control board. The trolling motor needs to be disconnected in some way from the batteries. Not doing so could damage the control board when charging the batteries and will result in the trolling motor drawing the batteries down over a time period.
John

Hey Jones, thanks for the heads up and technical explanation.

Good info, Thanks John. I know I am guilty of not doing this often enough and need to get into a better habit of doing so.