Your bracing etc looks OK to me. Of course that's not an opinion based on engineering expertise nor on strength & statics calculations, but on they way I have put together improvised lifting set-ups. That said I've seen (and used) a lot scarier set-ups.
BTW, I like the flag display as I have a Vietnam Era POW flag in my shop.
BTW, I like the flag display as I have a Vietnam Era POW flag in my shop.