How to replace laptop with Raspberry Pi in BenQ projector home theater system?

Question

HDMI

There is a debugged home theater system: HDD - Laptop - Projector. In order not to use a laptop and make the whole system more mobile (for example, to take it to presentations or just watch a movie outside the home), the idea arose to replace it with a Raspberry Pi (any suitable model). Ideally, the new system should work like this: An HDD (1 TB) is connected to the Raspberry without external power, Raspberry transmits a signal to the projector (BenQ W700) only via HDMI, Raspberry receives power from the USB port built into the projector (USB type B - square, like printers).
Questions:
1. Is it possible to power the Raspberry from the projector's USB? Is there enough current to support the operation of an external HDD?
2. How efficient is such a video playback scheme in general? Will fullHD content slow down on R-pi?
3. If any additional modules are required, then tell me which ones?
Comments: I do not consider connecting via a VGA adapter, because significantly affect the quality of the image.
If someone has had experience with such a connection, I would be grateful to hear your feedback. Thank you!

Answer 1

1. Why RPi if for this functionality a regular Android flash drive is enough, designed specifically for working with video, and it costs less than RPi and also takes up less space, looks more beautiful.
2. Without a tambourine, food cannot be taken away. There is no power output on the projector. If you only disassemble the projector, find a 5V line on the PSU and solder USB to it.
3. Why VGA if you have two HDMIs, use them.

Answer 2

without item 1 looks workable

Answer 3

It is quite realistic if:
1) Raspberry pi Zero, enough for the video for the eyes.
2) As a hard SSD through an economical sata> usb 2.0 converter (this stuff can be safely powered directly from a USB raspberry without any hubs)
A zero raspberry will eat about 500mA. The rest is on the SSD, but enough! And the HDD is fucking eating (1A minimum is needed to start), it’s in the trash