Dock lines; I carry 2 different colors, Gold ones are 15' the white ones are 25 or 30'. That way I can grab the right length for the task. 3/8 or 1/2 both work your choice.
A basic 80 pc tool set should be fine, a pump-out fitting, Crescent wrench, screw drivers, Allen set. After you get the boat get your nut-driver set out and check every hose clamp. There are stories of one being loose somewhere. I carry a qt of engine oil never opened it, I also carry a qt of out-drive gear lube, this I have used, ask the dealer to give you one.
As for the Vacuflush use with RV paper, we have one and never regretted it. I leave the switch ON at all times. The only time it gets turned off is when the master battery switch is off.