Dear Denise,
The answer as below information;
1. How can we fill in water and how can we leak the water out, because with water, it is very heavy to carry around. ; as video Leak Water
2. Briefly explain on warranty; 1 Year
3. Briefly explain on how to adjust pressure and how it works; as video link 1 / link 2 / link 3
4. Do you have DRY leakage tester - not using water? ; Yes, We have. (video: Dry Test) .
You want to test both machine or test one by one machine? If you want to test one by one, I will offer 1 unit.