Yes, please be sure to run the unit with warm soapy water for 20-30 minutes prior to initial use, also ensuring that all connections are secure and tight to prime the unit.

12 gallons

The wheels are 8.5 inches in diameter.

We do not know of any ways to conventionally add a pressure gauge to the sprayer. We do not offer the option and anything you would attempt at that point would be at your own discretion.

Adjustable pressure .95GPM/3.6L pump with up to 80 PSI

The removable toolbox contains your pump, you can remove the toolbox to easily change out your pump or battery if ever needed.

The 12AH lead acid battery provides 4X the battery life of other lithium battery sprayers. Sprays For 6-8 hours on a single battery charge or over 200 gallons of solution so that you can spray all day

The Beast features a wide mouth lid and opening that is just under 6 inches wide.

"Leaking commonly occurs when the nozzle pieces have not been fully tightened. Connections can come loose over time, so check your nozzle connections and re-tighten before each use and whenever you switch out your nozzles. Be sure to wrap all the connection points with provided plumbers tape you'll find in your accessories bag, whenever using liquid under pressure, there is a potential for leaks. If trouble persists, don't hesitate to reach out to support at 1-800-613-6889 for additional help."

You can fill the tank half way for sure, no need to use a full tank if that's not what you need, simply remove the drain cap when you are finished to drain any unused solution.