Sounds pretty normal to me. I like a horse to stand in tack for awhile as part of the breaking process. Usually I take the stirrups off so they can't get hung on anything; and I used to keep an old ratty saddle that I didn't care about for exactly this purpose. 4 hours doesn't sound excessive. Nothing's hurting the pony here, he's just learning patience and tolerance.
I also usually let a greenie stand in bitting rig - loose ring or rubber snaffle, surcingle and side reins for 1 - 2 hours at a time. I adjust the side reins so that the horse has to learn to give to release the pressure. It's ideal, IMO, just to leave the horse alone in his stall to work this out for himself. When I see the horse standing quietly, not fighting and giving to the pressure; then I'll do a little long rein work and establish steering and brakes. He may very well fight the rig at first and hurt his mouth, but I want him to associate that pain with his fighting, not with me or anything I'm doing.
I also don't have a problem backing a horse the first day.
As far as earning trust or creating a bond, a good trainer does that *by* working with the horse in this manner, and being a leader. A lot of the NH games and exercises that "earn trust" or "create a bond" are long, slow routes to this goal for handlers that aren't comfortable in the role of alpha or leader. A calm, confident, authoritative trainer doesn't need these exercises because he/she is secure in that role and can communicate that to the horse readily. You may be confusing the means with the end.