I'm not aware of any lights that have a DMX terminator built it. Regardless, it can't hurt using a DMX terminator.
For such a short run, and for testing purposes, 25-feet is OK for XLR cabling. Do switch to DMX cabling when you can. It may look the same inside and out, but it's different. Don't let the schematic fool you.
I agree with Jingles in the fact that you don't need to start so high up in the DMX addressing range. Start low, build up. I generally start at 1.
My lighting addressing is done to be compatible with myDMX Operator and MyDMX. I have some small gaps, but it's to faciliate the Scanner buttons on my DMX Operator. 1 addressing scheme for 2 controller situations.