What does Homey Bridge add to a smart home?

What does Homey Bridge add to a smart home?

Radio’s for Zigbee, Z-Wave, BLE, 433 Mhz and a Infrared Transmitter in your Home with a connection you your Homey (cloud). And that makes Homey with a Homey Bridge the Basic (entry level) Homey solution als you describe in your first alinea.

I am sure there is much more possible with the bridge than without, if that still doesn’t fulfill all your needs you probably need a Homey Pro.
Please check the Athom website to compare possibilities, scroll down to :
Not sure which Homey is right for you? Here’s our product lineup.
and check the Apps you need in the App store. or on the status page -The new Homey — Beta Status | Homey or on the community topic about available Apps (with some explanation and discussion) Homey (cloud / bridge version), a selection of available apps (WIKI)

Yes and No,
Nope, not more than the small note you received with it to setup Homey Bridge with the App.
Yes, all is online as you can see and general usage for both Homey and Homey Pro is the same, the specific differences are most in the Sections Homey Pro vs Homey Bridge.
and there als is a Blog but keep is mind the older material is created with the Homey Pro. Some apps may not (yet) be available for Homey Bridge of maybe never will be.