The issue you have is that it falls within multiple jurisdictions - most or all of whom have no financial incentive to pay for the dredging which will cost a bomb. Look at the shite fight that took place to get a commitment to dredge Raby Bay boat ramp basin because no one wanted to put their hand up and pay. Even dredging of the ferry basin at Cleveland was put off because one of the ferry operators reportedly said they were not paying. If a facility like that can't get government funding for safer access, 1770 has little to no hope. Most river bar entrances will be non navigable at some stage of a tide - the response you are most likely to get will be " the safety of the vessel is the responsibility of the vessels master. If it is not safe to cross, wait until such time that it is."
As for rescues in the area - last time we sailed to Port Alma from Bundaberg, there was a report of a vessel that had sunk and left 6 people in the water. The various rescue groups simply put a lot of effort into contacting available vessels in the area to attend. The closest vessel raised (Bundaberg based charter vessel) was diverted before the report was downgraded to the vessel was making it's way to 1770 at reduced speed but under it's own power. At this point a GBRMPA patrol vessel was asked to shadow the vessel to port. The area is pretty busy now - unless the weather is extremely bad, we never do a transit without seeing vessel traffic.