I'm doing Law now and the cutoff last year was 95.9 or something similar... it's sure to go up. The Lighthouse scheme doesn't make the entry UAI lower, I think they just take into consideration disadvantages/circumstances. I was under the impression that the only scheme that lets you in on a lower UAI was the EAS (through the HSC). if you applied for this during the HSC, you should be fine, but if you haven't, I think the Lighthouse is there for you to present your case and see whether they accept you or not.
(And also, you need to have proof of your disadvantages (ie. letters from psychologists) and also show that you can handle the workload for whichever course you're trying to get in to... so academic proof)
Hope this helps!