Financial is high - it used to say so in previous versions of the calc that if you're on Centrelink, just set financial disadvantage to high (fun fact: I never saw my family as poor. When I was told that just having Centrelink meant I counted as the highest form of financial disadvantage, I was dumbstruck lol)
Medical conditions - it depends on what those conditions are, but even if you told us, we probably wouldn't be able to tell you what to do put anyway. What you should do is use the calculator twice - once at none, and once at high, and that'll give you a range of ATARs that you might possibly get with SEAS. If you're doing this for goal setting, it may be worth setting your goals as if your medical conditions weren't accepted - that way, if they are, you'll get a nice bonus for yourself. In truth, you won't really know how much your SEAS help you out - you can make guesses if you look into it, but VCAA aren't going to tell you much.
Having said that, if you're applying for Monash and are worried your medical conditions won't help,
it's worth clicking here to look at the Monash Guarantee, because you qualify for it just by being on Centrelink payments. (you didn't mention that you were on Centrelink payments or if you have a LIHCC, but your parent being on Family Tax Benefit A counts)