How close to the wall does it need to be?

As an ultra short throw projector it sits inches from the wall or screen and throws the image upward. Exact throw distance depends on the screen size you want, so check Sharp's throw ratio chart before you mount it.

Is the laser light source worth it over a lamp projector?

The laser is rated for 20,000 hours in standard mode, so you avoid lamp replacements for years of normal use. It also reaches full brightness quickly and holds brightness better over its life than a lamp.

Does it have built-in apps like Netflix?

No. It is a display with HDMI and USB inputs, so you need a streaming stick, set-top box or computer connected to it for apps.

What resolution does it actually project?

It projects 1920x1200 (WUXGA), a 16:10 panel. It accepts 2160p input and downscales it, and it supports HDR10.

Can I connect a soundbar or speakers?

Yes. It has Bluetooth, so you can pair wireless speakers or a soundbar. Wired audio options depend on the ports on your source device.

Is it good for a bright room?

LCD with a laser source holds up better in ambient light than dim home-theater projectors, but a UST projector still looks best with blinds closed or a light-rejecting screen.