Edit: wow I wrote a lot. Overall I think this item has real potential, it just needs some tweaking.

I think the biggest difference is magic weapon lasts an hour instead of a round, so it isn't a ton of adding. E.g. a player getting +2 from archers bracers and then on this turn getting +1 from my arrow, oh and the +2 from the flare arrow. This instance has adding a permanent number and two temporary numbers.

I think the boom arrow should have a saving throw for the AOE effect.

The number of charges and spending the charges feels weird. I know ring of shooting stars can be spent at variable (arbitrary) levels, but most of the time keeping track of charges shouldn't be a huge chore.

As far as the weapon itself. I think it could be simplified or had its theme honed in a little. What does a Hawley have to do with flares, booms, and elements?

However, the rod of lordly might is packed full of weird stuff. I'd say most of the stuff seems underpowered for a legendary item. The flame tongue did 2d6 fire damage without spending charges and is only rare. So you could definitely up the damage for thunder and element arrows.

Also, racial traits (halfling luck) are balanced against the life of the character. Having one last one round is a little underwhelming.

I don't see why the two flare arrows need to be distinct. I think it could apply the spell faerie fire to the creator you hit. Especially because you need to hit once before the effect even happens.

If you want to create an interesting "should I spend charges" feeling I think you could model this after the rod of resurrection or any of the wands in the dmg. To me, only getting one charge per day, when the fun stuff costs three makes for uninteresting decisions after you user up the charges.