1、Is the outdoor unit completely waterproof? I need something to use at an unprotected driveway gate.
Yes, it completely waterproof !
2、I want a system for security. When someone comes to my door, I want to be able to converse with them, to know who they are and what they want.
Thank you for your questions, you can search :Hosmart 1500FT Wireless 7-Channel Digital FM Wireless Intercom with Outdoor Doorbell Intercom system (include 18650 battery)
3、Do I need a 4-unit system to use this as a doorbell intercom? I need something for my office when clients arrive I can talk to them.
Of course, you can use a 4-unit system. it can works fine.
4、Hello... if i buy the 1pcs receiver+1pcs transmitter usd 64.99, do i need any other gear, or just need this? do i need an intercom?
These two items will communicate without other parts. U need 120 v power to the lower item in the pix, and batteries (supplied unit) for the upper item. The provided battery looks like it will last 3-4 months, in an outdoor environment.
5、How do you recharge the batteries in the outside unit and how long does it take to fully charge?
The outside unit needs to charge with AC adapter or an USB port for approximately 4 to 5 hours.
6、can i add one more indoor station to this ?
Of course, you can.
7、Is the outside unit as loud as the inside unit?
The volume of the outside unit is loud enough to use, but not as loud as the inside unit
8、I know this doorbell has a battery, but can I also power it from my current doorbell wiring?
They all come with a micro usb slot. Typical door bells I think run at 12volts.
